Skip to content
EvidenceHelixEvidenceLib · Scientific Encyclopedia
⌘ K

Scientific library

EvidenceLib encyclopediaAll articles A–Z2,835Open textbooks209Open-access articles1,406Cancer study catalog458How it is made

My workspace this browser

Saved pages0Notes & annotations0

Recently viewed

Explore by field

Cancer and Oncology182Genetics and Genomics170Neuroscience185Cardiovascular Medicine180Immunology142Pharmacology173Molecular Biology161Infectious Diseases150Rare and Inherited Diseases181Clinical Research173Anatomy and Physiology613Drugs and Chemicals621Psychiatry and Psychology185Public Health and Nutrition178Diagnostics and Medical Technology125Respiratory Medicine113Digestive System and Liver91Metabolism and Endocrine Disease177Bones, Joints, Muscles and Skin213Kidney, Urology and Women's Health173Eye, Ear, Nose and Throat55
Plans & pricingCompare EvidenceHelix workspace plans
Library›Open-access articles›Article

Continue where you left off ()

Explore more with EvidenceHelix Workspace

Compare studies, analyze evidence and create research reports with premium tools.

Explore Researcher plans

EvidenceLib · Open-access article · Kidney, Urology and Women's Health

Antenatal magnesium sulphate and adverse neonatal outcomes: A systematic review and meta-analysis

Emily Shepherd, Rehana A. Salam, Deepak Manhas, Anne Synnes, Philippa Middleton, Maria Makrides, Caroline A. Crowther

PLoS Medicine 2019 · doi:10.1371/journal.pmed.1002988

CC BY 4.0Full textApproximately 47 min read224 references

Table of Contents

AbstractKey pointsIn this articleIntroductionMethodsResultsDiscussionSupporting informationReferences

Abstract

Background

There is widespread, increasing use of magnesium sulphate in obstetric practice for pre-eclampsia, eclampsia, and preterm fetal neuroprotection; benefit for preventing preterm labour and birth (tocolysis) is unproven. We conducted a systematic review and meta-analysis to assess whether antenatal magnesium sulphate is associated with unintended adverse neonatal outcomes.

Methods and findings

CINAHL, Cochrane Library, LILACS, MEDLINE, Embase, TOXLINE, and Web of Science, were searched (inceptions to 3 September 2019). Randomised, quasi-randomised, and non-randomised trials, cohort and case–control studies, and case reports assessing antenatal magnesium sulphate for pre-eclampsia, eclampsia, fetal neuroprotection, or tocolysis, compared with placebo/no treatment or a different magnesium sulphate regimen, were included. The primary outcome was perinatal death. Secondary outcomes included pre-specified and non-pre-specified adverse neonatal outcomes. Two reviewers screened 5,890 articles, extracted data, and assessed risk of bias following Cochrane Handbook and RTI Item Bank guidance. For randomised trials, pooled risk ratios (RRs) or mean differences, with 95% confidence intervals (CIs), were calculated using fixed- or random-effects meta-analysis. Non-randomised data were tabulated and narratively summarised. We included 197 studies (40 randomised trials, 138 non-randomised studies, and 19 case reports), of mixed quality. The 40 trials (randomising 19,265 women and their babies) were conducted from 1987 to 2018 across high- (16 trials) and low/middle-income countries (23 trials) (1 mixed). Indications included pre-eclampsia/eclampsia (24 trials), fetal neuroprotection (7 trials), and tocolysis (9 trials); 18 trials compared magnesium sulphate with placebo/no treatment, and 22 compared different regimens. For perinatal death, no clear difference in randomised trials was observed between magnesium sulphate and placebo/no treatment (RR 1.01; 95% CI 0.92 to 1.10; 8 trials, 13,654 babies), nor between regimens. Eleven of 138 non-randomised studies reported on perinatal death. Only 1 cohort (127 babies; moderate to high risk of bias) observed an increased risk of perinatal death with >48 versus ≤48 grams magnesium sulphate exposure for tocolysis. No clear secondary adverse neonatal outcomes were observed in randomised trials, and a very limited number of possible adverse outcomes warranting further consideration were identified in non-randomised studies. Where non-randomised studies observed possible harms, often no or few confounders were controlled for (moderate to high risk of bias), samples were small (200 babies or fewer), and/or results were from subgroup analyses. Limitations include missing data for important outcomes across most studies, heterogeneity of included studies, and inclusion of published data only.

Conclusions

Our findings do not support clear associations between antenatal magnesium sulphate for beneficial indications and adverse neonatal outcomes. Further large, high-quality studies (prospective cohorts or individual participant data meta-analyses) assessing specific outcomes, or the impact of regimen, pregnancy, or birth characteristics on these outcomes, would further inform safety recommendations. PROSPERO: CRD42013004451.

Key points

  • CINAHL, Cochrane Library, LILACS, MEDLINE, Embase, TOXLINE, and Web of Science, were searched (inceptions to 3 September 2019).
  • Randomised, quasi-randomised, and non-randomised trials, cohort and case–control studies, and case reports assessing antenatal magnesium sulphate for pre-eclampsia, eclampsia, fetal neuroprotection, or tocolysis, compared with placebo/no treatment or a different magnesium sulphate regimen, were included.
  • Secondary outcomes included pre-specified and non-pre-specified adverse neonatal outcomes.
  • Our findings do not support clear associations between antenatal magnesium sulphate for beneficial indications and adverse neonatal outcomes.
  • Further large, high-quality studies (prospective cohorts or individual participant data meta-analyses) assessing specific outcomes, or the impact of regimen, pregnancy, or birth characteristics on these outcomes, would further inform safety recommendations.

Sentences taken unchanged from the authors’ abstract, as a reading aid. Not a new analysis and not medical advice.

In this article

  1. Introduction: Antenatal magnesium sulphate is commonly used in obstetric practice. Systematic reviews and clinical practice guidelines support its use when given for maternal neuroprotection in pre-eclampsia or eclampsia [1–3] and for neuroprotection of the fetus in women at risk of preterm birth (for cerebral palsy prevention) [4–7].
  2. Methods: We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline; the relevant checklist is provided in S1 PRISMA Checklist. Prior to conduct, this systematic review was registered with PROSPERO (International Prospective Register of Systematic Reviews; CRD42013004451) [18].
  3. Discussion: Overall, no clear difference in our primary review outcome, perinatal death, was shown in the randomised trials comparing antenatal magnesium sulphate with placebo/no treatment, nor in regimen comparisons in randomised trials. While 11 of the 138 non-randomised studies reported on perinatal death, only 1 cohort study (at moderate to high risk of bias) observed a…

Opening sentences of each section, unchanged.

Introduction

Antenatal magnesium sulphate is commonly used in obstetric practice. Systematic reviews and clinical practice guidelines support its use when given for maternal neuroprotection in pre-eclampsia or eclampsia [1–3] and for neuroprotection of the fetus in women at risk of preterm birth (for cerebral palsy prevention) [4–7]. Despite continued use in some countries [8], available evidence does not support its role in preventing preterm birth in women with, or following, threatened preterm labour (for tocolysis) [7,9].

Concerns surrounding possible unintended adverse outcomes for fetuses or neonates following exposure to antenatal magnesium sulphate emerged over 50 years ago [10,11], and uncertainty persists today. While the clinical consequences of hypermagnesemia, related to increased serum concentrations, are well known and documented (such as lethargy, drowsiness, flushing, nausea, vomiting, muscle weakness, loss of deep tendon reflexes, hypotension, apnoea, coma, cardiac arrest, and, ultimately, death [12]), whether neonates are at risk of such adverse outcomes following exposure to antenatal magnesium sulphate is unclear.

We have systematically reviewed the maternal adverse effects of different antenatal magnesium sulphate regimens [13], and a further systematic review has summarised the effects specifically on fetal heart rate [14]. To our knowledge, a broad evaluation of evidence surrounding potential unintended neonatal adverse outcomes, informed by current guidance [15–17], has not previously been conducted. Implementation of this treatment may be strengthened, and its safety improved, if guidelines and recommendations for practice can be based on such knowledge.

The aim of our study, therefore, was to conduct a comprehensive systematic review to assess whether antenatal magnesium sulphate is associated with perinatal death and other unintended adverse neonatal outcomes.

Methods

We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline; the relevant checklist is provided in S1 PRISMA Checklist. Prior to conduct, this systematic review was registered with PROSPERO (International Prospective Register of Systematic Reviews; CRD42013004451) [18]. The Australian Cerebral Palsy Alliance Research Foundation–funded review protocol is available in S1 Text. Ethical approval was not required.

Search strategy

Comprehensive searches of the bibliographic databases CINAHL, Cochrane Library, LILACS, MEDLINE, Embase, TOXLINE, and Web of Science were undertaken from their respective inceptions to 3 September 2019, using combinations of MeSH and free text terms. The search strategies are available in S2 Text. No date or language restrictions were applied; however, because of logistical constraints, for non-English papers, only those with an available English abstract or full-text translation were retrieved. The reference lists of eligible articles were checked for additional reports.

Inclusion criteria

We included randomised and quasi-randomised controlled trials as well as non-randomised controlled studies (non-randomised trials, cohort studies, and case–control studies), and case reports. We excluded cross-sectional studies and case series. We included studies available as abstracts only, along with full-text publications.

We included neonates who were exposed to antenatal magnesium sulphate, regardless of their gestational age at exposure or birth. We included studies where antenatal magnesium sulphate was given for pre-eclampsia or eclampsia, for neuroprotection of the fetus, or for tocolysis. We excluded studies where magnesium sulphate was given as an adjuvant during obstetric anaesthesia. We included intervention studies in which magnesium sulphate was compared with no treatment, placebo, or a different magnesium sulphate regimen. We included observational studies where magnesium sulphate was assessed as an ‘exposure’. We excluded studies where magnesium sulphate was compared with another therapy (for example, diazepam for pre-eclampsia or eclampsia, or nifedipine for tocolysis).

We included studies that reported on adverse outcomes for neonates, however defined. The primary outcome was perinatal death. Secondary outcomes included pre-specified adverse outcomes (based on non-systematic literature review: stillbirth, neonatal death or death up to hospital discharge, low Apgar scores at 1 and 5 minutes, need for active resuscitation at birth, respiratory depression, spontaneous intestinal perforation, patent ductus arteriosus, hypotension, lethargy, hypotonia or hyporeflexia, osteopenia or bone fractures, neonatal intensive care unit admission, and duration of neonatal care unit admission), along with other non-pre-specified adverse neonatal outcomes.

Study selection

After screening all titles and abstracts, we obtained full-text articles for studies that appeared to meet the inclusion criteria. All full-text articles were assessed for inclusion. Each stage was carried out by 2 reviewers, and we resolved any discrepancies through discussion, or, if required, we consulted a third reviewer.

Data extraction and management

For included studies, data were extracted using a standardised form, including information regarding design, participants, the magnesium sulphate regimen(s), the control/comparison if applicable, neonatal adverse outcomes reported, results relevant to the review, and the risk of bias. For all randomised trials, all case reports, and 60% of non-randomised studies, extraction was carried out by 2 reviewers (for 40% of non-randomised studies, extractions were checked by a second reviewer), and we resolved discrepancies through discussion, or, if required, we consulted a third reviewer.

Assessment of risk of bias

Quality appraisal of intervention studies was undertaken utilising established guidelines provided in the Cochrane Handbook for Systematic Reviews of Interventions [19]. The quality assessment of observational studies was guided by the RTI Item Bank [20].

Data synthesis and analysis

Data analyses were undertaken by study design. Statistical analyses for randomised trials were performed using Review Manager, version 5.3 [21]. We present quantitative data from individual studies as risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, with 95% confidence intervals (CIs). For all outcomes, we carried out analyses as far as possible on an intention-to-treat basis. Pooled estimates were calculated using fixed-effects meta-analysis (Mantel-Haenszel method) where there was a sufficient quantity of data, with clinical homogeneity. Where there was substantial statistical heterogeneity (where I2 was greater than 30% and either T2 was greater than 0 or there was a low P value [less than 0.10] in the χ2 test), summary estimates were calculated using random-effects meta-analysis. Where there were 10 or more trials in a meta-analysis, we investigated reporting biases (such as publication bias) using funnel plots, which we assessed visually.

Separate comparisons were performed for those studies assessing magnesium sulphate versus no treatment/placebo and those comparing different magnesium sulphate regimens. For our primary review outcome (perinatal death) and other mortality outcomes, we conducted subgroup analyses based on indication for use and characteristics of the magnesium sulphate loading and maintenance dose regimens, as these factors were considered likely to influence outcomes. It was not possible to conduct subgroup analyses based on other pregnancy or birth characteristics (gestational age at magnesium sulphate administration, birthweight, mode of birth, and concomitant maternal treatments) due to paucity of data. We assessed subgroup differences by interaction tests available within Review Manager, and, where applicable, we have quoted the χ2 statistic and P value, and the interaction test I2 value.

For observational studies (non-randomised trials, cohort studies, and case–control studies), we present effect estimates where possible as adjusted RRs or odds ratios if reported with 95% CIs, unadjusted RRs or odds ratios with 95% CIs, P values only, or percentages (rates), in tabular format; we used narrative synthesis to summarise the studies. Data from case reports were grouped according to common adverse outcomes, tabulated, and summarised narratively.

Results

Study selection

The results of the search strategy, including the sources of the studies, their assessment, and final inclusion are shown in Fig 1. The database searching identified 5,890 records, and other searching identified a further 11 records. Review of the titles and abstracts and exclusion of irrelevant and duplicate records yielded 777. Of these, we excluded 572 for the documented reasons (see S3 Text for list of records excluded due to absence of an English translation). We included a total of 205 articles, relating to 197 studies. See S4 Text for references for all included studies. In the case of multiple publications from the same study, we included the report with the most relevant data as the primary reference, and only included further publications as secondary references if they provided additional relevant data.

Fig 1 Flow diagram of included studies.Flow diagram showing the flow of records through the different phases of the review, indicating the number of records identified, included and excluded, and the reasons for exclusions. (Figure not reproduced here; see the original article.)

Evidence from randomised controlled trials

Forty randomised trials were included, the characteristics of which are detailed in S1 Table, and the risk of bias assessments are summarised in Fig 2, S1 Fig, and S2 Table [22–61]. The trials assessed a range of different magnesium sulphate regimens with varying control groups, and are therefore assessed under 8 different comparisons:

  1. Magnesium sulphate versus placebo or no treatment (18 trials)
  2. Lower versus higher dose regimens of magnesium sulphate (8 trials)
  3. Intramuscular (IM) versus intravenous (IV) maintenance dose of magnesium sulphate (5 trials)
  4. Loading versus loading and maintenance dose of magnesium sulphate (5 trials)
  5. Serial IV boluses versus continuous IV infusion of magnesium sulphate (1 trial)
  6. Short versus standard maintenance of magnesium sulphate (1 trial)
  7. Slower versus standard rate of loading dose infusion of magnesium sulphate (1 trial)
  8. Weaning versus no weaning of maintenance of magnesium sulphate (1 trial)

Fig 2 Risk of bias for randomised controlled trials.Risk of bias graph showing judgements about each risk of bias item presented as percentages across the 40 included randomised trials. (Figure not reproduced here; see the original article.)

The methodological quality of the 40 trials varied considerably. Considering selection bias, 18 trials were at low risk, reporting adequate methods for sequence generation and allocation concealment. Twelve and 8 trials received an unclear judgement for 1 and 2 of the selection bias domains, respectively. Two trials appeared to be quasi-randomised and thus were at high risk of selection bias. Twelve trials were at low risk of performance and detection bias (with blinding of participants, personnel, and outcome assessors); 21 were at high risk of both performance and detection bias (all trials of different magnesium sulphate regimens, with no reported blinding), and the remaining 7 trials had an unclear judgement for 1 or 2 of the blinding domains. The majority of trials (31) were at low risk of attrition bias for neonatal outcome data, though for 9 trials, this was unclear. Only 5 trials were at low risk of reporting bias, 1 was at high risk of reporting bias, and for the remaining 34 trials, selective reporting was unclear.

Magnesium sulphate versus placebo or no treatment

This comparison included 18 trials. The indication for use of magnesium sulphate in 6 trials was the prevention of eclampsia [30,32,39,43,48,61]; in 6 trials, fetal neuroprotection [28,36,45,47,51,54]; and in 6 trials, the prevention of preterm birth (tocolysis) [33–35,38,40,46]. Magnesium sulphate regimens assessed varied considerably: 4-gram IV loading dose only (2 trials), 4-gram IV loading dose and 1-gram-per-hour IV maintenance dose (4 trials), 4-gram IV loading dose and 2-gram-per-hour IV maintenance (4 trials), 6-gram IV loading dose and 2-gram-per-hour IV maintenance dose (6 trials), and 4-gram IV and 10-gram IM loading dose and 5-gram IM maintenance dose every 4 hours (2 trials), with duration of treatment generally ranging from 12 to 24 hours. Fourteen trials compared magnesium sulphate with a placebo, while 4 trials had a no-treatment comparison (see Table 1 and S1 Appendix for effect estimates, forest plots, and funnel plots).

Table 1 Adverse outcome estimates from randomised controlled trials: Comparison 1—Magnesium sulphate versus placebo or no treatment.
OutcomeStudiesParticipantsMethod (I2)RR (95% CI)
1.1 Perinatal death813,654F (23%)1.01 (0.92, 1.10)
1.2 Stillbirth912,340F (0%)0.99 (0.87, 1.12)
1.3 Neonatal death1112,987F (21%)1.00 (0.86, 1.17)
1.4 Death > 28 days, before discharge510,691F (0%)0.96 (0.60, 1.53)
1.5 Early neonatal death19,024F (NA)1.09 (0.86, 1.37)
1.6 Late neonatal death19,024F (NA)1.54 (0.95, 2.49)
1.7 Apgar score < 7 at 1 minute2199F (17%)1.67 (1.02, 2.73)
1.8 Apgar score < 7 at 5 minutes512,729F (0%)1.02 (0.92, 1.14)
1.9 Meconium at birth1210F (NA)1.55 (0.89, 2.72)
1.10 Intubated at birth311,364F (30%)0.95 (0.87, 1.04)
1.11 Resuscitation in the delivery room
 1.11.1 Any12,416F (NA)0.99 (0.96, 1.03)
 1.11.2 Oxygen bag, mask, or both12,416F (NA)1.07 (0.98, 1.17)
 1.11.3 Chest compressions12,416F (NA)1.11 (0.73, 1.71)
1.12 Respiratory distress syndrome73,639R (46%)0.95 (0.79, 1.14)
1.13 Transient tachypnoea of the newborn2243F (0%)0.96 (0.52, 1.77)
1.14 Surfactant187F (NA)0.88 (0.62, 1.24)
1.15 Mechanical ventilation512,751R (63%)1.01 (0.94, 1.09)
1.16 Non-invasive ventilation1688F (NA)1.03 (0.93, 1.15)
1.17 Oxygen required1153F (NA)0.95 (0.67, 1.35)
1.18 Chronic lung disease54,513F (0%)1.06 (0.96, 1.17)
1.19 Apnoea and bradycardia2841F (0%)1.23 (0.98, 1.53)
1.20 Pneumothorax187F (NA)2.44 (0.26, 22.52)
1.21 Pulmonary haemorrhage187F (NA)2.44 (0.52, 11.41)
1.22 Necrotising enterocolitis84,804F (0%)1.21 (0.98, 1.51)
1.23 Sepsis42,694R (31%)0.83 (0.54, 1.28)
1.24 Hypoglycaemia on NICU admission134F (NA)0.63 (0.06, 6.34)
1.25 Poor feeding190F (NA)No events
1.26 Patent ductus arteriosus32,536F (26%)0.97 (0.80, 1.17)
1.27 Hypotension23,103F (22%)1.03 (0.89, 1.19)
1.28 Volume expansion187F (NA)2.03 (1.01, 4.10)
1.29 Mean blood pressure < 10th centile in the first 24 hours187F (NA)1.30 (0.67, 2.53)
1.30 Superior vena cava flow < 41 ml/kg/min in the first 24 hours187F (NA)1.22 (0.62, 2.40)
1.31 Right ventricular output < 120 ml/kg/min in the first 24 hours187F (NA)1.08 (0.51, 2.30)
1.32 Dobutamine187F (NA)1.73 (0.84, 3.57)
1.33 Dopamine187F (NA)2.17 (0.62, 7.62)
1.34 Any inotrope187F (NA)1.54 (0.82, 2.92)
1.35 Retinopathy of prematurity12,415F (NA)0.99 (0.85, 1.14)
1.36 Generalised hypotonicity12,415F (NA)1.03 (0.77, 1.37)
1.37 Seizures411,397F (0%)0.78 (0.57, 1.06)
1.38 Hyperbilirubinaemia190F (NA)2.00 (0.19, 21.28)
1.39 Intraventricular haemorrhage104,891F (0%)0.95 (0.85, 1.06)
1.40 Intraventricular haemorrhage, grade 3 or 463,769F (19%)0.81 (0.60, 1.09)
1.41 Periventricular leucomalacia44,225F (0%)0.93 (0.68, 1.28)
1.42 Any white matter injury1665F (NA)0.87 (0.62, 1.22)
1.43 Severe white matter injury1688F (NA)0.85 (0.55, 1.32)
1.44 Severe white matter injury or death1688F (NA)0.92 (0.66, 1.28)
1.45 Persistent parenchymal echogenicity18,260F (NA)1.09 (0.66, 1.81)
1.46 Echodensity in children born < 32 weeks11,613F (NA)0.38 (0.19, 0.79)
1.47 Echolucency
 1.47.1 In all children11,776F (NA)0.62 (0.37, 1.03)
 1.47.2 In children born < 32 weeks11,613F (NA)0.61 (0.38, 0.97)
1.48 Ventriculomegaly210,036F (0%)0.98 (0.68, 1.42)
1.49 Any of echodensity, echolucency, intraventricular haemorrhage, periventricular haemorrhage, or ventriculomegaly
 1.49.1 In all children11,776F (NA)0.85 (0.69, 1.06)
 1.49.2 In children born < 32 weeks11,613F (NA)0.92 (0.78, 1.09)
1.50 Composite adverse outcome11,776F (NA)0.62 (0.37, 1.03)
1.51 NICU admission38,519F (17%)1.00 (0.95, 1.06)
1.52 Intensive care unit stay (days)1120MD, F (NA)0.02 (−0.17, 0.21)
1.53 Hospital stay (days)2257MD, R (99%)−2.75 (–8.92, 3.43)
1.54 Special care baby unit admission > 7 days or death19,024F (NA)1.01 (0.95, 1.08)
1.55 Special care baby unit admission > 7 days18,260F (NA)1.02 (0.93, 1.11)
1.56 Still in hospital at 6 weeks19,024F (NA)0.99 (0.06, 15.80)

No clear difference was seen between magnesium sulphate and placebo/no treatment for the primary review outcome perinatal death (RR 1.01; 95% CI 0.92 to 1.10; 8 trials, 13,654 babies; analysis 1.1), nor for stillbirth, neonatal death (no obvious asymmetry observed on visual assessment of funnel plot), death later than 28 days but before discharge, early neonatal death, or late neonatal death (Table 1; S1 Appendix). When considering indication for use, the tocolysis subgroup showed an increase in perinatal death (RR 7.99; 95% CI 1.00 to 63.49; 2 trials, 257 babies; analysis 1.1.1) that was not observed in the pre-eclampsia or fetal neuroprotection subgroups. The subgroup interaction test, however, did not indicate a differential effect according to treatment indication (χ2 = 4.07, P = 0.13, I2 = 50.8%). For the remaining mortality outcomes, subgroup interaction tests did not indicate differential treatment effects according to indication for administration (see Tables 2 and 3 for effect estimates for individual subgroups and results from subgroup interaction tests).

Table 2 Subgroup analyses based on indication for use from randomised controlled trials: Comparison 1—Magnesium sulphate versus placebo or no treatment.
Outcome and subgroupStudiesParticipantsMethod (I2)RR (95% CI)χ2, P value, I2
1.1 Perinatal death
1.1.1 Tocolysis2257F (NA)7.99 (1.00, 63.49)4.07, 0.13, 50.8%
1.1.2 Pre-eclampsia29,259F (0%)1.01 (0.91, 1.13)
1.1.3 Fetal neuroprotection44,138F (0%)0.96 (0.80, 1.15)
1.2 Stillbirth
1.2.1 Tocolysis2257F (NA)5.70 (0.28, 116.87)1.45, 0.49, 0%
1.2.2 Pre-eclampsia39,961F (8%)0.99 (0.87, 1.12)
1.2.3 Fetal neuroprotection42,122F (0%)0.85 (0.40, 1.80)
1.3 Neonatal death
1.3.1 Tocolysis4445R (61%)0.78 (0.11, 5.67)0.48, 0.79, 0%
1.3.2 Pre-eclampsia29,259R (35%)1.03 (0.64, 1.65)
1.3.3 Fetal neuroprotection53,283R (0%)0.86 (0.68, 1.08)
1.4 Death > 28 days, before discharge
1.4.1 Tocolysis3412F (0%)0.76 (0.19, 3.09)0.37, 0.83, 0%
1.4.2 Pre-eclampsia19,024F (NA)1.13 (0.55, 2.31)
1.4.3 Fetal neuroprotection11,255F (NA)0.88 (0.44, 1.74)
Table 3 Subgroup analyses based on regimen characteristics from randomised controlled trials: Comparison 1—Magnesium sulphate versus placebo or no treatment.
Outcome or subgroupStudiesParticipantsMethod (I2)RR (95% CI)χ2, P value, I2
Subgroups based on LD
1.1 Perinatal death
1.1.4 4-g IV LD52,259R (42%)0.96 (0.62, 1.49)0.57, 0.75, 0%
1.1.5 6-g IV LD12,136R (NA)1.12 (0.85, 1.47)
1.1.6 4-g IV and 10-g IM LD29,259R (0%)1.01 (0.91, 1.12)
1.2 Stillbirth
1.2.4 4-g IV LD62,961F (0%)1.25 (0.85, 1.84)1.57, 0.21, 36.1%
1.2.5 6-g IV LD1120F (NA)No events
1.2.6 4-g IV and 10-g IM LD29,259F (0%)0.96 (0.84, 1.10)
1.3 Neonatal death
1.3.4 4-g IV LD62,294R (7%)0.86 (0.64, 1.16)0.44, 0.80, 0%
1.3.5 6-g IV LD31,434R (2%)0.83 (0.48, 1.44)
1.3.6 4-g IV and 10-g IM LD29,259R (35%)1.03 (0.64, 1.65)
1.4 Death > 28 days, before discharge
1.4.4 4-g IV LD31,514F (0%)0.81 (0.43, 1.53)0.81, 0.67, 0%
1.4.5 6-g IV LD1153F (NA)2.47 (0.10, 59.70)
1.4.6 4-g IV and 10-g IM LD19,024F (NA)1.13 (0.55, 2.31)
Subgroups based on MD
1.1 Perinatal death
1.1.7 LD only2747R (0%)0.92 (0.59, 1.44)2.73, 0.44, 0%
1.1.8 1-g/hour IV MD11,255R (NA)0.81 (0.60, 1.09)
1.1.9 2–5-g/hour IV MD32,393R (71%)2.27 (0.35, 14.55)
1.1.10 5-g/4-hour IM MD29,259R (0%)1.01 (0.91, 1.12)
1.2 Stillbirth
1.2.7 LD only2747F (0%)0.96 (0.22, 4.17)2.50, 0.48, 0%
1.2.8 1-g/hour IV MD21,957F (9%)1.22 (0.81, 1.83)
1.2.9 2–5-g/hour IV MD3377F (0%)5.70 (0.28, 116.87)
1.2.10 5-g/4-hour IM MD29,259F (0%)0.96 (0.84, 1.10)
1.3 Neonatal death
1.3.7 LD only2747R (0%)0.93 (0.58, 1.47)0.72, 0.87, 0%
1.3.8 1-g/hour IV MD11,255R (NA)0.81 (0.59, 1.11)
1.3.9 2–5-g/hour IV MD61,726R (41%)0.84 (0.30, 2.33)
1.3.10 5-g/4-hour IM MD29,259R (35%)1.03 (0.64, 1.65)
1.4 Death > 28 days, before discharge
1.4.7 1-g/hour IV MD11,255F (NA)0.88 (0.44, 1.74)0.37, 0.83, 0%
1.4.8 2–5-g/hour IV MD3412F (0%)0.76 (0.19, 3.09)
1.4.9 5-g/4-hour IM MD19,024F (NA)1.13 (0.55, 2.31)

Babies exposed to antenatal magnesium sulphate had a 67% relative increase in the risk of having an Apgar score less than 7 at 1 minute (RR 1.67; 95% CI 1.02 to 2.73; 2 trials, 199 babies; analysis 1.7), and over 2 times the risk of need for volume expansion compared with babies not exposed (RR 2.03; 95% CI 1.01 to 4.10; 1 trial, 87 babies; analysis 1.28). A subgroup of babies born less than 32 weeks gestation exposed to antenatal magnesium sulphate had a 62% relative reduction in the risk of intracerebral echodensity, compared with babies not exposed (RR 0.38; 95% CI 0.19 to 0.79; 1 trial, 1,613 babies; analysis 1.46). While a difference in intracerebral echolucency was not observed in all babies, a 39% relative reduction was seen for babies born less than 32 weeks exposed to antenatal magnesium sulphate (RR 0.61; 95% CI 0.38 to 0.97; 1 trial, 1,613 babies; analysis 1.47.2) (Table 1; S1 Appendix).

There were no clear differences between magnesium sulphate and placebo/no treatment for all remaining secondary outcomes reported (Table 1; S1 Appendix).

Lower versus higher dose regimens

This comparison included 8 trials, with 6 assessing magnesium sulphate for treatment of eclampsia or severe pre-eclampsia [22,23,44,52,56,59], and 2 for the prevention of preterm birth (tocolysis) [26,60]. Regimens assessed varied: lower dose regimens included a 4- to 10-gram loading dose with a 0.625- to 2-gram-per-hour maintenance dose; higher dose regimens assessed included a 4- to 14-gram loading dose with a 1.25- to 5-gram-per-hour maintenance dose (see Table 4 and S1 Appendix for effect estimates and forest plots).

Table 4 Adverse outcome estimates from randomised controlled trials: Comparison 2—Lower versus higher dose regimens of magnesium sulphate.
OutcomeStudiesParticipantsMethod (I2)RR (95% CI)
2.1 Perinatal death6543F (0)1.01 (0.75, 1.36)
2.2 Stillbirth5471F (0)0.94 (0.61, 1.45)
2.3 Neonatal death6535F (0)1.12 (0.57, 2.22)
2.4 Apgar score < 7 at 1 minute3302F (0)0.96 (0.68, 1.35)
2.5 Apgar score < 7 at 5 minutes3302R (35%)1.41 (0.54, 3.65)
2.6 Resuscitation164F (NA)1.00 (0.22, 4.59)
2.7 Respiratory distress syndrome2154R (53%)1.97 (0.76, 5.15)
2.8 Respiratory depression150F (NA)0.33 (0.04, 2.99)
2.9 Respiratory disorders164F (NA)1.08 (0.87, 1.33)
2.10 Mechanical ventilation164F (NA)2.00 (0.39, 10.16)
2.11 Bradycardia1104F (NA)3.85 (0.45, 33.29)
2.12 Jaundice150F (NA)1.25 (0.38, 4.12)
2.13 Hypoglycaemia1104F (NA)0.96 (0.06, 14.98)
2.14 Hypocalcaemia1104F (NA)2.89 (0.12, 69.32)
2.15 Hypotonia150F (NA)0.14 (0.02, 1.08)
2.16 Requirement for calcium gluconate150F (NA)0.25 (0.06, 1.06)
2.17 NICU admission5409F (6%)1.75 (1.06, 2.88)
2.18 NICU stay (days)1104MD, F (NA)3.10 (0.78, 5.42)

No clear differences between the lower and higher dose regimens of magnesium sulphate were seen for the primary review outcome perinatal death (RR 1.01; 95% CI 0.75 to 1.36; 6 trials, 543 babies; analysis 2.1), nor for stillbirth or neonatal death (Table 4; S1 Appendix). For all mortality outcomes, subgroup interaction tests did not indicate differential treatment effects according to indication for administration of antenatal magnesium sulphate (see Table 5 for effect estimates for individual subgroups and results from subgroup interaction tests).

Table 5 Subgroup analyses based on indication for use from randomised controlled trials: Comparison 2—Lower versus higher dose regimens of magnesium sulphate.
Outcome and subgroupStudiesParticipantsMethod (I2)RR (95% CI)χ2, P value, I2
2.1 Perinatal death
2.1.1 Tocolysis1104F (NA)2.25 (0.61, 8.21)1.63, 0.20, 38.6%
2.1.2 Pre-eclampsia/eclampsia5439F (0%)0.94 (0.70, 1.28)
2.2 Stillbirth
2.2.1 Tocolysis1104F (NA)0.96 (0.06, 14.98)0.00, 0.99, 0%
2.2.2 Pre-eclampsia/eclampsia4367F (0%)0.94 (0.60, 1.46)
2.3 Neonatal death
2.3.1 Tocolysis1104F (NA)2.89 (0.61, 13.65)1.99, 0.16, 49.6%
2.3.2 Pre-eclampsia/eclampsia5431F (0%)0.82 (0.37, 1.82)

Babies exposed to the lower dose versus higher dose regimens of magnesium sulphate had an increased risk of neonatal intensive care unit admission (RR 1.75; 95% CI 1.06 to 2.88; 5 trials, 409 babies; analysis 2.17). On average, babies exposed to the lower dose regimen had a longer duration of stay in the neonatal intensive care unit compared with those exposed to the higher dose regimen (MD 3.10 days; 95% CI 0.78 to 5.42; 1 trial, 104 babies; analysis 2.18) (Table 4; S1 Appendix).

No clear differences were seen between the lower and higher dose regimens of magnesium sulphate for the remaining secondary outcomes reported (Table 4; S1 Appendix).

IM versus IV maintenance dose

This comparison included 5 trials, all assessing magnesium sulphate for the prevention or treatment of eclampsia [27,31,49,55,58]. Regimens assessed included Bhattacharjee’s regimen (4-gram IV loading dose; 6-gram IV maintenance dose every 8 hours), Dhaka regimen (4-gram IV and 6-gram IM loading dose; 2.5-gram IM maintenance dose every 4 hours), Pritchard’s regimen (4-gram IV and 10-gram IM loading dose; 5-gram IM maintenance dose every 4 hours), Zuspan’s regimen (4-gram IV loading dose; 1-gram IV maintenance dose every hour), and Sibai’s regimen (6-gram IV loading dose; 2-gram IV maintenance dose every hour) (all maintenance doses were for 24 hours after birth or last seizure) (see Table 6 and S1 Appendix for effect estimates and forest plots).

Table 6 Adverse outcome estimates from randomised controlled trials: Comparisons 3–8.
Outcome and subgroupStudiesParticipantsMethod (I2)RR (95% CI)
Comparison 3: IM versus IV maintenance dose of magnesium sulphate (pre-eclampsia/eclampsia)
3.1 Perinatal death
 3.1.1 Pritchard’s versus Zuspan’s regimen2353F (0%)0.94 (0.66, 1.32)
 3.1.2 Pritchard’s versus Sibai’s regimen1115F (NA)0.90 (0.53, 1.53)
 3.1.3 Pritchard’s versus Bhattacharjee’s regimen1107F (NA)1.28 (0.61, 2.65)
 3.1.4 Dhaka versus Zuspan’s regimen141F (NA)0.57 (0.16, 2.08)
3.2 Stillbirth
 3.2.1 Pritchard’s versus Zuspan’s regimen1114F (NA)0.79 (0.44, 1.40)
 3.2.2 Pritchard’s versus Sibai’s regimen2133F (0%)0.80 (0.46, 1.41)
 3.2.3 Pritchard’s versus Bhattacharjee’s regimen1107F (NA)1.18 (0.38, 3.63)
 3.2.4 Dhaka versus Zuspan’s regimen141F (NA)0.24 (0.03, 1.95)
3.3 Neonatal death
 3.3.1 Pritchard’s versus Zuspan’s regimen1114F (NA)2.52 (0.27, 23.47)
 3.3.2 Pritchard’s versus Sibai’s regimen1115F (NA)2.56 (0.27, 23.93)
 3.3.3 Pritchard’s versus Bhattacharjee’s regimen1107F (NA)1.37 (0.47, 4.06)
 3.3.4 Dhaka versus Zuspan’s regimen141F (NA)1.90 (0.19, 19.40)
3.4 Apgar score < 7 at 1 minute
 3.4.1 Dhaka versus Zuspan’s regimen141F (NA)0.32 (0.10, 1.01)
3.5 Apgar score < 7 at 5 minutes
 3.5.1 Dhaka versus Zuspan’s regimen141F (NA)0.38 (0.08, 1.74)
3.6 Respiratory distress syndrome
 3.6.1 Dhaka versus Zuspan’s regimen141F (NA)0.76 (0.24, 2.44)
3.7 Jaundice
 3.7.1 Dhaka versus Zuspan’s regimen141F (NA)0.76 (0.24, 2.44)
3.8 Hypotonia
 3.8.1 Dhaka versus Zuspan’s regimen141F (NA)0.48 (0.10, 2.32)
3.9 NICU admission
 3.9.1 Pritchard’s versus Zuspan’s regimen1114F (NA)0.98 (0.35, 2.73)
 3.9.2 Pritchard’s versus Sibai’s regimen1115F (NA)1.00 (0.36, 2.78)
 3.9.3 Dhaka versus Zuspan’s regimen141F (NA)0.76 (0.24, 2.44)
Comparison 4: Loading dose versus loading and maintenance doses of magnesium sulphate (pre-eclampsia/eclampsia)
4.1 Perinatal death3632R (63%)0.94 (0.33, 2.72)
4.2 Stillbirth3803F (26%)1.10 (0.77, 1.58)
4.3 Neonatal death2462F (0%)0.78 (0.43, 1.41)
4.4 Neonatal death < 7 days1402F (NA)0.73 (0.30, 1.77)
4.5 Apgar score < 7 at 0 minutes152F (NA)1.07 (0.32, 3.54)
4.6 Apgar score < 7 at 1 minute152F (NA)0.86 (0.06, 12.98)
4.7 Apgar score < 7 at 5 minutes2406F (NA)1.61 (0.72, 3.62)
4.8 NICU admission for respiratory distress2397F (0%)1.02 (0.63, 1.65)
4.9 NICU admission for early onset sepsis180F (NA)1.00 (0.06, 15.44)
4.10 NICU admission for late onset sepsis180F (NA)3.00 (0.13, 71.51)
4.11 NICU admission for meconium aspiration syndrome180F (NA)1.00 (0.06, 15.44)
4.12 NICU admission for birth asphyxia180F (NA)0.33 (0.01, 7.95)
4.13 NICU admission3435F (0%)0.94 (0.77, 1.15)
Comparison 5: Serial intravenous boluses versus continuous intravenous maintenance of magnesium sulphate (pre-eclampsia)
5.1 Perinatal death1197F (NA)0.44 (0.08, 2.34)
5.2 Stillbirth1197F (NA)0.29 (0.01, 7.09)
5.3 Neonatal death1197F (NA)0.58 (0.10, 3.42)
5.4 Intubated at birth1197F (NA)0.88 (0.29, 2.62)
5.5 Mechanical ventilation1197F (NA)0.44 (0.11, 1.70)
5.6 Bradycardia (<110 bpm)1197F (NA)0.44 (0.08, 2.34)
5.7 Special care baby unit admission1197F (NA)0.84 (0.53, 1.35)
Comparison 6: Short versus standard maintenance course of magnesium sulphate (eclampsia)
6.1 Stillbirth198F (NA)0.87 (0.41, 1.82)
6.2 Birth asphyxia198F (NA)0.83 (0.24, 2.92)
Comparison 7: Slower versus standard rate of loading dose of magnesium sulphate (fetal neuroprotection)
7.1 Stillbirth151F (NA)0.35 (0.01, 8.12)
Comparison 8: Weaning versus no weaning of magnesium sulphate (tocolysis)
8.1 Apgar score < 7 at 5 minutes1141F (NA)0.65 (0.22, 1.90)

No clear differences were observed for

  • Pritchard’s versus Zuspan’s regimen for the primary review outcome perinatal death (RR 0.94; 95% CI 0.66 to 1.32; 2 trials, 353 babies; analysis 3.1.1), nor for stillbirth or neonatal death;
  • Pritchard’s versus Sibai’s regimen for the primary review outcome perinatal death (RR 0.90; 95% CI 0.53 to 1.53; 1 trial, 115 babies; analysis 3.1.2), nor for stillbirth or neonatal death;
  • Pritchard’s versus Bhattacharjee’s regimen for the primary review outcome perinatal death (RR 1.28; 95% CI 0.61 to 2.65; 1 trial, 107 babies; analysis 3.1.3), nor for stillbirth or neonatal death;
  • Dhaka versus Zuspan’s regimen for the primary review outcome perinatal death (RR 0.57; 95% CI 0.16 to 2.08; 1 trial, 41 babies; analysis 3.1.4), nor for stillbirth or neonatal death (Table 6; S1 Appendix).

No clear differences were observed for Pritchard’s versus Zuspan’s regimen, Pritchard’s versus Sibai’s regimen, or Dhaka versus Zuspan’s regimen for the remaining secondary outcomes reported (Table 6; S1 Appendix).

Loading dose versus loading and maintenance doses

This comparison included 5 trials, all assessing magnesium sulphate for the prevention or treatment of eclampsia [25,41,50,53,57]. Trials compared a cumulative 8-, 10-, or 14-gram loading dose (4 grams IV and 4 to 10 grams IM) with Dhaka or Pritchard’s regimen (see descriptions above; and see Table 6 and S1 Appendix for effect estimates and forest plots).

No clear differences for loading dose only versus loading and maintenance dose regimens were seen for the primary review outcome perinatal death (average RR 0.94; 95% CI 0.33 to 2.72; 3 trials, 632 babies; analysis 4.1), nor for stillbirth, neonatal death, or neonatal death at less than 7 days (Table 6; S1 Appendix).

No clear differences for loading dose only versus loading and maintenance dose regimens were seen for the remaining secondary outcomes reported (Table 6; S1 Appendix).

Serial IV boluses versus continuous IV maintenance dose

This comparison included 1 trial, assessing magnesium sulphate for the treatment of severe pre-eclampsia, and compared a serial intravenous bolus regimen (6-gram IV loading dose, and 2-gram IV bolus over 10 minutes every 2 hours as maintenance) with a continuous infusion (4-gram IV loading dose, and 1-gram-per-hour continuous IV maintenance dose) [37] (see Table 6 and S1 Appendix for effect estimates and forest plots).

No clear differences between the serial bolus and continuous infusion regimens were seen for the primary review outcome perinatal death (RR 0.44; 95% CI 0.08 to 2.34; 1 trial, 197 babies; analysis 5.1), nor for stillbirth or neonatal death (Table 6; S1 Appendix).

No clear differences between the serial bolus and continuous infusion regimens were seen for the remaining secondary outcomes reported (Table 6; S1 Appendix).

Short versus standard maintenance course

This comparison included 1 trial, assessing magnesium sulphate for the treatment of eclampsia. Both groups received a 4-gram IV and 10-gram IM loading dose, followed by either a short maintenance course (2 doses of 5 grams IM 4 hours apart after birth or last seizure) or a standard maintenance course (5 grams IM every 4 hours for 24 hours after birth or last seizure) [29].

No clear difference between the short and standard maintenance course regimens was seen for stillbirth. No clear difference between the short and standard maintenance course regimens was seen for the only other secondary outcome reported, birth asphyxia (see Table 6 and S1 Appendix for effect estimates and forest plots).

Slower versus standard rate of loading dose

This comparison included 1 trial, assessing magnesium sulphate for fetal neuroprotection, and compared a slower (over 60 minutes) versus standard (over 20 minutes) rate of administering a 4-gram IV loading dose of magnesium sulphate (all women received a 1-gram-per-hour maintenance dose for 24 hours or until birth) [24].

No clear difference between a slower and standard rate of loading dose administration was seen for stillbirth (see Table 6 and S1 Appendix for effect estimate and forest plot).

Weaning versus no weaning

This comparison included 1 trial, assessing magnesium sulphate for the prevention of preterm birth (tocolysis), and compared weaning (by 1 gram IV per 4 hours) versus not weaning magnesium sulphate (all women received a 6-gram IV loading dose, and 2- to 3.5-gram IV maintenance dose per hour until tocolysis was achieved) [42].

No clear difference between weaning and no weaning was seen for Apgar score less than 7 at 5 minutes (see Table 6 and S1 Appendix for effect estimate and forest plot).

Evidence from non-randomised comparative studies

One hundred thirty-eight non-randomised studies were included: 5 non-randomised trials, 35 prospective cohort studies (7 with nested case–control analyses), 82 retrospective cohort studies (16 with nested case–control analyses), 8 non-concurrent cohort studies, and 8 case–control studies [62–199]. The characteristics of the studies and risk of bias assessments are detailed in S1 and S2 Tables.

There was substantial variation in the characteristics of these studies regarding participants, indications for use of magnesium sulphate (prevention or treatment of eclampsia: 30 studies; prevention of preterm birth (tocolysis): 28 studies; fetal neuroprotection: 25 studies; combination of aforementioned indications: 38 studies; unclear: 17 studies), comparison groups, outcomes assessed (and their definitions), and analysis methods employed. Methodological quality (specifically in relation to the risk of bias for reported review outcomes of interest) also differed across the studies, with overall judgements of unclear (specifically when only abstracts were available), high, moderate to high, and moderate risk of bias assigned to 43 studies, 49 studies, 35 studies, and 11 studies, respectively. The most common concerns across studies related to the potential for confounding (with no attempt to balance allocation between groups or match groups, and/or important confounding variables not taken into account in relevant outcome analyses), detection bias (with the consistent implementation of valid and reliable measures being unclear, and/or the absence of blinding of exposure or outcome assessors), and performance bias (with protocols not available to assess important variations).

The primary review outcome, perinatal death, was reported by 11 of the 138 non-randomised studies, 10 of which showed either a possible reduction (or lower rate) or no clear difference (or similar rate) in perinatal death among babies exposed to magnesium sulphate compared with no magnesium sulphate or a different magnesium sulphate regimen. A possible increase in perinatal death, specifically among babies exposed to >48 versus ≤48 grams of magnesium sulphate for tocolysis was shown in in the 11th study (retrospective cohort of 127 babies, moderate to high risk of bias) [183]. See Table 7 and S3 Table for summaries of individual study results.

Table 7 Perinatal death from non-randomised studies.
Study; designParticipantsComparisonsResults summary
Adama-Hondegla 2013; RCS with CCS(N)178 babies born to women with eclampsia(1) Babies living at seventh day of life, N = 147 babies, versus (2) stillbirths and neonatal deaths in first 7 days, N = 31 babiesMgSO4 exposure: aOR 1.04, P > 0.05
Alexander 2006; PCS87 babies born to women with eclampsia(1) No gestational hypertension, no MgSO4, N = 49 babies, versus (2) gestational hypertension, MgSO4, N = 11 babies, versus (3) gestational hypertension, no MgSO4, N = 27 babiesPerinatal death: 6.1% (3/49) versus 0% (0/11) versus 11.1% (3/27)
Cawyer 2019; RCS2,468 babies born to women with pre-eclampsia >32 weeks GA(1) MgSO4, N = 1,353 babies, versus (2) no MgSO4, N = 1,115 babiesPerinatal or neonatal death: 0.1% (2/1,353) versus 0.2% (2/1,115), P = 1.00
Chowdhury 2009; PCS529 babies born to women with eclampsia(1) MgSO4 Pritchard’s regimen, N = 406 babies, versus (2) MgSO4 low dose IV regimen, N = 123 babiesPerinatal death: OR 1.58, 95% CI 0.93–2.61, P = 0.075
Jung 2018; RCS184 babies born to women with ROM <32 weeks GA(1) MgSO4 for tocolysis, N = 143 babies, versus (2) no MgSO4, N = 41 babiesPerinatal death: Overall: 7.0% (10/143) versus 19.5% (8/41), P = 0.0375; ROM at 23 to 27+6 weeks GA: 14.3% (9/63) versus 36.8% (7/19), P = 0.0651; ROM at 28 to 31+6 weeks GA: 1.25% (1/80) versus 4.5% (1/22), P = 0.9051
Kamilya 2005; CCS(N)1,205 babies born to women with eclampsia(1) Birth year 2002–2004 (almost universal MgSO4), N = 481 babies, versus (2) birth year 1995–1997 (no MgSO4), N = 724 babiesPerinatal death: 24.3% (117/481) versus 54.8% (397/724)
Kamyar 2016a; RCS (secondary analysis RCT)396 babies born to women with intrapartum clinical chorioamnionitis(1) MgSO4 for fetal neuroprotection, N = 192 babies, versus (2) placebo, N = 204 babiesStillbirth or death by 1 year: Overall: aRR 1.68, 95% CI 0.85–3.32; ≤28 weeks GA: aRR 1.34, 95% CI 0.47–2.73
Mitani 2011; RCS425 babies born between 22 and 31 weeks GA(1) MgSO4 for tocolysis, N = 236 babies, versus (2) no MgSO4, N = 189 babiesPerinatal death: 5.5% (13/236) versus 9.0% (17/189), P = 0.185
Okusanya 2012; NRT103 babies born to women with severe pre-eclampsia or eclampsiaSevere pre-eclampsia: (1) 10-g MgSO4 LD, N = 25 babies, versus (2) 14-g MgSO4 LD, N = 30 babiesPerinatal death, unclear reporting: Severe pre-eclampsia: (1) PMR 240 per 1,000 (6 deaths) versus (2) PMR 35 per 1,000 (1 death)
Eclampsia: (1) 10-g MgSO4 LD, N = 29 babies, versus (2) 14-g MgSO4 LD, N = 19 babiesPerinatal death, unclear reporting: Eclampsia: (1) PMR 241 per 1,000 (6 deaths, all IUFD) versus (2) 0 deaths
Scudiero 2000; RCS with CCS(N)127 babies born between 700 and 1,249 g, to women who received MgSO4 for tocolysis(1) Perinatal deaths, N = 18 babies, versus (2) survivors, N = 109 babiesMgSO4 > 48 g: 72.2% (13/18) versus 45.0% (49/109), P = 0.03; MgSO4 ≤ 48 g versus >48 g (multivariable model): OR 4.72, 95% CI 1.12 to 19.97, P = 0.035
(1) MgSO4 ≤ 24 g, N = 43 babies, versus (2) MgSO4 > 24 to ≤ 48 g, N = 25 babies, versus (3) MgSO4 > 48 g, N = 59 babiesPerinatal death (Cochrane–Armitage trend test, 1 versus 2 versus 3): 7.0% (3/43) versus 8.0% (2/25) versus 22.0% (13/59), P = 0.03; perinatal death (1 versus 2): 7.0% (3/43) versus 8.0% (2/25), P = 1.0
Young 1977; NRT144 babies born to women with pre-eclampsia or eclampsia(1) MgSO4 IV bolus MD (2 g over 10 minutes every 1–2 hours), N = 97 babies, versus (2) MgSO4 continuous IV MD (1 g per hour), N = 47 babiesPerinatal death: 2.1% (2/97) versus 2.1% (1/47)

For the majority of secondary pre-specified and non-pre-specified adverse neonatal outcomes reported, the results from non-randomised studies were consistent with those observed in randomised controlled trials, with no clear differences (and in some cases, possible benefits of magnesium sulphate) observed. The direction of the findings (no clear difference, possible benefit, possible harm, or mixed) from the non-randomised studies are summarised in Table 8, with the detailed individual study results provided in S3 Table.

Table 8 Summary of outcomes from non-randomised studies.
OutcomeDirection of effect for magnesium sulphate versus no magnesium sulphate or a different regimen
Studies showing no clear differenceStudies showing possible benefitStudies showing possible harm
StillbirthBrazy 1982; Chowdhury 2009*; Jung 2018^Jung 2018^; Shamsuddin 2005*Das 2015*
Neonatal death or death before dischargeAlston 2016; Ambadkar 2019; Basu 2012; Bertello Grecco 2019*; Brazy 1982; Canterino 1999; Chowdhury 2009*; De Jesus 2015; del Moral 2007; de Veciana 1995; Drassinower 2015; Elimian 2002*; Elliott 2003; Farkouh 2001; Gibbins 2013; Girsen 2015; Gonzalez-Quintero 2001; Hechtman 2002*; Hong 2019; James 2015; Jazayeri 2003; Jung 2018; Kamyar 2015a; Kamyar 2015b; Kamyar 2016a; Kamyar 2016b^; Kimberlin 1998; Lee 2013; Lloreda-Garcia 2016; Mikhael 2019*; Morag 2016; Narasimhulu 2017; Nassar 2006*; Özlü 2019; Paneth 1997; Rantonen 2001; Shalabi 2017^; Shokry 2010; Suh 2015; Weisz 2015^; Whitsel 2004; Yokoyama 2010Downey 2017; Garcia Alonso 2018; Grether 1998; Shalabi 2017^; Stockley 2018; Weisz 2015^Das 2015*;Kamyar 2016b^; Lipsitz 1971*; Rattray 2014; Rauf 2017
Apgar score < 7 at 1 minute (or ≤ 5)Chun 2014^; Gibbins 2013; Lloreda-Garcia 2016; Mitani 2011; Morag 2016; Narasimhulu 2017Chun 2014^; Das 2015*; Girsen 2015; Lipsitz 1971*
Apgar score < 7 at 5 minutes (or ≤5 or <6)Canterino 1999; Chun 2014^; Cuff 2018*; de Veciana 1995; Drassinower 2015; Elimian 2002*; Gibbins 2013; Jung 2018; Lloreda-Garcia 2016; McPherson 2014*; Mitani 2011; Narasimhulu 2017; Nassar 2006*; Nelson 1995; Okusanya 2012*; Rhee 2012; Schanler 1997; Stockley 2018; Weisz 2015*Jeanneteau 2014; Shalabi 2017Chun 2014^; Das 2015*; Girsen 2015; Lipsitz 1971*; Morag 2016
Birth asphyxiaMcGuiness 1980Shamsuddin 2005*
Meconium at birthGreenberg 2013; Jazayeri 2003
IntubationBasu 2012; De Jesus 2015; Derks 2016; Morag 2016; Narasimhulu 2017; Weisz 2015*^Bajaj 2018; Drassinower 2015; Weisz 2015^Das 2015*; Rauf 2017; Weisz 2015*^
Intubation (duration)de Veciana 1995O Reilly 2016^O Reilly 2016*^
ResuscitationBasu 2012; Brookfield 2015*; De Jesus 2015; Garcia Alonso 2018; Gibbins 2013; Lloreda-Garcia 2016; McPherson 2014*; Narasimhulu 2017; Özlü 2019; Weisz 2015*^Bajaj 2018; De Silva 2018Lipsitz 1971*; Weisz 2015^
Oxygen bag, mask, or both (resuscitation)Bajaj 2018; Drassinower 2015; Riaz 1998; Weisz 2015*^Weisz 2015*^
Chest compressions (resuscitation)Drassinower 2015; Stockley 2018; Weisz 2015*^Bajaj 2018; Weisz 2015^
Adrenaline (resuscitation)Stockley 2018; Weisz 2015*^Jeanneteau 2014; Weisz 2015^
Score for Neonatal Acute Physiology > 10 or 20 in first 24 hoursStockley 2018; Weisz 2015^Deering 2005; Shalabi 2017; Weisz 2015*^
Delayed adaptationLai 2017; Riaz 1998Brazy 1982
Respiratory distress syndromeAlston 2016; Ambadkar 2019; Bozkurt 2016; Brookfield 2016; Canterino 1999; De Jesus 2015; de Veciana 1995^; Drassinower 2015; Elimian 2002*; Girsen 2015; Gonzalez-Quintero 2001; Gursoy 2015; Imamoglu 2014; Jazayeri 2003; Jung 2018; Kamyar 2015a; Lee 2013; McPherson 2014*; Mitani 2011; Rantonen 2001; Schanler 1997; Shokry 2010; Suh 2015; Yokoyama 2010de Veciana 1995^; Özlü 2019
Respiratory depressionBertello Grecco 2019*Das 2015*
Surfactant usedelValle 1998; Elimian 2002*; Garcia Alonso 2018; Lloreda-Garcia 2016; Rantonen 2001; Shokry 2010; Weisz 2015*
VentilationBrookfield 2016; De Jesus 2015^; Drassinower 2015; Garcia Alonso 2018; Girsen 2015; Havranek 2011; James 2015; Lee 2013; Lloreda-Garcia 2016^; McPherson 2014*; Nunes 2018; Özlü 2019; Rantonen 2001; Schanler 1997; Shokry 2010De Jesus 2015^; Lloreda-Garcia 2016^; Rauf 2017^; Shalabi 2017Lipsitz 1971*; Lloreda-Garcia 2016^; Rauf 2017^
Ventilation (duration)Black 2006; De Jesus 2015; Kimberlin 1998; Özlü 2019; Suh 2015
Methylxanthine use or durationBlack 2006; Havranek 2011; Imamoglu 2014; Schanler 1997
Chronic lung disease or bronchopulmonary dysplasiaAlston 2016; Basu 2012; Bozkurt 2016; De Jesus 2015; Edwards 2018; Garcia Alonso 2018; James 2015; Jung 2018; Kamyar 2015a; Kamyar 2016a; McPherson 2014*; Özlü 2019; Shalabi 2017; Stockley 2018; Suh 2015; Weisz 2015Narasimhulu 2017; Stetson 2019
Oxygen use (at 28 days, 36 weeks, or discharge)Kimberlin 1998; Morag 2016; Schanler 1997
Oxygen use (duration)De Jesus 2015; Özlü 2019; Suh 2015
Steroid use (dexamethasone or hydrocortisone)Mikhael 2019*; Rantonen 2001; Rattray 2014; Shalabi 2017
ApnoeaBozkurt 2016; Riaz 1998; Wutthigate 2017*
Pulmonary haemorrhageDe Jesus 2015; James 2015
Necrotising enterocolitisAlston 2016; Bozkurt 2016; Brazy 1982; De Jesus 2015; delValle 1998; de Veciana 1995; Downey 2017; Edwards 2018; Elimian 2002*; Elliott 2003; Garcia Alonso 2018; Ghidini 2001; Gursoy 2015; Hong 2019; James 2015; Jazayeri 2003; Jung 2018; Kamyar 2015a; Kamyar 2016a; Kamyar 2016b; Kimberlin 1998; Lee 2013; Lloreda-Garcia 2016; McPherson 2014*; Mikhael 2019*; Morag 2016; Narasimhulu 2017; Özlü 2019; Schanler 1997; Shalabi 2017; Stockley 2018; Suh 2015; Weisz 2015; Yokoyama 2010Moschos 2001; Wiswell 1996
Spontaneous intestinal perforationDowney 2017; Mikhael 2019*; Shalabi 2017Rattray 2014
Composite of necrotising enterocolitis/spontaneous intestinal perforation or deathKamyar 2016b*^; Mikhael 2019*^Downey 2017; Mikhael 2019*^Kamyar 2016b*^; Rattray 2014*
Necrotising enterocolitis/spontaneous intestinal perforation–associated deathHong 2019; Shalabi 2017
SepsisAlston 2016; Bozkurt 2016; De Jesus 2015; Elimian 2002*; Girsen 2015; James 2015; Jazayeri 2003; Jung 2018; Kamyar 2016a; Lloreda-Garcia 2016; Mikhael 2019*; Morag 2016; Özlü 2019; Rantonen 2001; Riaz 1998; Stockley 2018; Teng 2006; Weisz 2015Whitsel 2004
Antibiotic useElimian 2002*^; Greenberg 2013Elimian 2002^
HypoglycaemiaBozkurt 2016; Grimbly 2015
Feeding intoleranceGursoy 2015; Özlü 2019; Riaz 1998Belden 2017*
Delayed stoolingLloreda-Garcia 2016^Lloreda-Garcia 2016^Brazy 1982; Das 2015*
Meconium passage delayAmbadkar 2019; Lloreda-Garcia 2016
IleusBrazy 1982; Nakamura 1991*
Delayed voidingSahin 2001Das 2015*
Patent ductus arteriosusBasu 2012; Bozkurt 2016; delValle 1998; Elimian 2002*; Garcia Alonso 2018; Gursoy 2015; Imamoglu 2014; James 2015; Katayama 2011*^; Lee 2013*; Özlü 2019; Schanler 1997; Yokoyama 2010Qasim 2017Brazy 1982; del Moral 2007; Gonzalez-Quintero 2001; Katayama 2011^; Lee 2013; Narasimhulu 2017; Shokry 2010
Patent ductus arteriosus (treated)De Jesus 2015; del Moral 2007; delValle 1998; Katayama 2011*; Lee 2013; Lloreda-Garcia 2016; Mikhael 2019*; Shalabi 2017; Suh 2015Bonta 2000*
HypotensionBrazy 1982; Derks 2016; Drassinower 2015; Gursoy 2015; Morag 2016; Teng 2006De Jesus 2015Narasimhulu 2017
HypertensionGursoy 2015Brown 2019
Inotrope useImamoglu 2014; James 2015; Shokry 2010
Intravenous fluids and/or nutritional support neededGreenberg 2013; Rasch 1982
PhototherapyGreenberg 2013; Havranek 2011; Imamoglu 2014
Retinopathy of prematurityBasu 2012; Bozkurt 2016; Cuff 2018*; De Jesus 2015; Elliott 2003; Garcia Alonso 2018; Jung 2018; Kamyar 2015a; Kimberlin 1998; Lee 2013; McPherson 2014*; Narasimhulu 2017; Özlü 2019; Shalabi 2017^; Stockley 2018; Suh 2015; Weisz 2015; Yokoyama 2010Shalabi 2017^Rauf 2017
HypotoniaBertello Grecco 2019*; Drassinower 2015; Gibbins 2013; Girsen 2015; Nassar 2006*Ambadkar 2019; Brazy 1982; Das 2015*; Rauf 2017; Riaz 1998
SeizureDrassinower 2015; Girsen 2015; Kimberlin 1998; McPherson 2014*; Rauf 2017Shokry 2010
EncephalopathyGirsen 2015; Rantonen 2001; Rauf 2017
Intraventricular haemorrhageAlston 2016; Black 2006; De Jesus 2015; delValle 1998; de Veciana 1995; Drassinower 2015; Edwards 2018; Elliott 2003; Gano 2016; Garcia Alonso 2018; Gasparyan 2017; Gonzalez-Quintero 2001; Gursoy 2015; Hom 2018; Imamoglu 2014; Jazayeri 2003; Jung 2018^; Kamyar 2015a; Lee 2013; Leviton 1997; Martin 1998; McPherson 2014*; Mitani 2011*; Nassar 2006*; Nelson 1995; Özlü 2019; Paneth 1997; Schanler 1997; Stetson 2019; Stockley 2018; Suh 2015; Yokoyama 2010Jung 2018^; Kuban 1992; Perlman 1995; Petrova 2012; Rantonen 2001; Rauf 2017; Shokry 2010Salafia 1995
Intraventricular haemorrhage grade 3 or 4del Moral 2007; Downey 2017; Gano 2016; James 2015; Jung 2018; Kamyar 2016a; Kimberlin 1998; McPherson 2014*; Mikhael 2019*; Narasimhulu 2017; Özlü 2019; Rantonen 2001; Stockley 2018; Weintraub 2001Gasparyan 2017; Perlman 1995; Sarkar 2009; Wiswell 1996Cuff 2018*; Khodapanahandeh 2008
Periventricular leucomalaciaBozkurt 2016; De Jesus 2015; del Moral 2007; delValle 1998; Garcia Alonso 2018; Jung 2018^; Kamyar 2015a; Kamyar 2016a; Lee 2013; Mitani 2011*; Narasimhulu 2017; Rauf 2017; Suh 2015; Wiswell 1996FineSmith 1997; Jung 2018^; Murata 2005
Intraventricular haemorrhage or periventricular leucomalaciaBasu 2012; Canterino 1999*; Elimian 2002*
Intraventricular haemorrhage grade 3 or 4 and/or periventricular leucomalaciaBozkurt 2016; Canterino 1999*; Morag 2016; Shalabi 2017^; Weisz 2015Koksal 2002; Shalabi 2017^; Wiswell 1996
HypocalcaemiaCho 2014; Lee 2015; McGuiness 1980Narasimhulu 2017
Bone abnormalitiesYokoyama 2010Holcomb 1991*; Matsuda 1997*
Hearing impairment or hearing test failureJung 2018Leung 2016
Composite adverse outcomesDrassinower 2015; Duffy 2012; Kamyar 2015a; Kamyar 2015b; Kamyar 2015c; Kamyar 2016a; Mitani 2011*; Narasimhulu 2017; Palatnik 2019; Rizzolo 2019; Sakae 2017*^; Weisz 2015Boyle 2018; Sakae 2017*^
NICU admissionAmbadkar 2019*^; Bertello Grecco 2019*; Cawyer 2019; Chun 2014^; Gibbins 2013; Lai 2017; McPherson 2014*; Rantonen 2001; Riaz 1998*Ambadkar 2019*^; Chun 2014^; Das 2015*; Girsen 2015; Greenberg 2011*; Greenberg 2013*; Rhee 2012
NICU durationGibbins 2013; Girsen 2015; Greenberg 2013; Jazayeri 2003; Jung 2018; Kimberlin 1998; Rauf 2017Narasimhulu 2017
Hospital stay durationAlston 2016; Basu 2012; De Jesus 2015; de Veciana 1995; Özlü 2019; Riaz 1998; Schanler 1997; Suh 2015Brazy 1982; Girsen 2015
Other (outcomes reported by single studies)Black 2006; Blackwell 2002; Brazy 1982; Derks 2016; Gano 2016; Girsen 2015; Greenberg 2013; Havranek 2011; Hong 2019; Imamoglu 2014; Jeanneteau 2014; Jones 2018; Jung 2018; Katayama 2011*; Kelly 1992; Kimberlin 1998; Lai 2017; Leviton 1997; Lloreda-Garcia 2016; Mittendorf 2005*; Morag 2016; Nassar 2006*; Nunes 2018; Özlü 2019; Paneth 1997; Petrov 2013; Rantonen 2001; Riaz 1998; Sahin 2001; Schanler 1997; Shalabi 2017^Deering 2005; Derks 2016; Gano 2016; Jeanneteau 2014; Kimberlin 1998; Mittendorf 2005*; Petrov 2013Belden 2017*; Brazy 1982; Das 2015*; Katayama 2011; Lai 2017; Lipsitz 1971*; Mittendorf 2009*; Morag 2015; Morag 2016; Rasch 1982; Shalabi 2017^; Verma 2006*; Weisz 2015; Whitten 2015

Seventeen of the 138 non-randomised studies (14 at moderate or moderate to high risk of bias, and 3 at unclear risk of bias [abstracts only]) observed a possible increase in the risk of adverse neonatal outcomes with antenatal magnesium sulphate, with some consideration of important confounding variables in relevant outcome analyses [68,73,84,90,106,108,109,129,132,134,140,152,153,173,180,184,191]. Potential increased risks with antenatal magnesium sulphate of 4 outcomes (discussed below) were observed by more than 1 study. For the remaining outcomes (nosocomial infection [184], enteral feeding intolerance [68], respiratory disease composite [153], pulmonary interstitial emphysema [191], early germinal matrix/intraventricular haemorrhage [180], thalamostriate or mineralising vasculopathy [152], and a composite neonatal adverse outcome [73]), single studies reported possible harms.

Potential increased risk of neonatal death before intensive care unit discharge, and of a composite outcome of neonatal death before intensive care unit discharge and/or necrotising enterocolitis, was shown among a subgroup of babies born less than 26 weeks gestation with the use of antenatal magnesium sulphate for fetal neuroprotection (293 babies, in a retrospective cohort of 697 babies born less than 28 weeks gestation) [129]. A possible increased risk of the composite outcome spontaneous intestinal perforation or neonatal death was also shown among a subgroup of babies born less than 25 weeks gestation with higher cumulative antenatal magnesium sulphate doses for fetal neuroprotection (non-concurrent cohort of 155 babies born less than 1,000 grams) [173].

A possible increased risk of patent ductus arteriosus was observed with magnesium sulphate given for pre-eclampsia (retrospective cohort of 81 ‘very low birthweight’ babies; abstract only) [140] or for pre-eclampsia or tocolysis (retrospective cohort of 941 babies born 500 to 1,000 grams) [90]. Further, a possible increased risk of patent ductus arteriosus in babies born 26 weeks gestation or later was shown with cumulative antenatal magnesium sulphate doses for pre-eclampsia or tocolysis of at least 50 grams (retrospective cohort of 941 babies born 500 to 1,000 grams) [90]. Potential increased risk of symptomatic patent ductus arteriosus, and of failure of early closure of the ductus arteriosus, was also observed with the use of antenatal magnesium sulphate for tocolysis (retrospective cohort of 160 babies born less than 28 weeks gestation, who all received indomethacin prophylaxis) [132].

A potential increased risk of intraventricular haemorrhage grade 3 or 4 was observed with antenatal magnesium sulphate for tocolysis (case–control study of 121 babies born less than 1,500 grams) [134], and with a higher dose regimen of antenatal magnesium sulphate for fetal neuroprotection (6-gram IV loading dose and 2-gram-per-hour IV maintenance dose for 12 hours versus 4-gram IV loading dose only) (retrospective cohort, including 54 babies exposed to magnesium sulphate within 12 hours of birth) [84].

A possible increased risk of neonatal intensive care unit admission with the use of antenatal magnesium sulphate for pre-eclampsia was observed (retrospective cohorts of 264 babies and 2,166 babies born at 37 weeks gestation or later) [106,109]. Further increased risks of neonatal intensive care unit and special care unit admission were observed with higher total hours, higher total doses, more than 12 hours, and more than 30 grams of antenatal magnesium sulphate for pre-eclampsia (retrospective cohort of 242 babies born at 35 weeks gestation or later) [108].

Evidence from case reports

Nineteen reports describing a total of 134 babies exposed to antenatal magnesium sulphate with adverse outcomes were included [200–218] (see Table 9; the detailed characteristics of cases are presented in S4 Table).

Table 9 Summary of main adverse outcomes from case reports.
OutcomeIndication for use: studies
Neonatal deathTocolysis: Herschel 2001
Pre-eclampsia/eclampsia: Kurtoglu 2000
Cardiopulmonary arrest after gentamicin exposure following hypermagnesemia at birthPre-eclampsia: L’Hommedieu 1983; Rasch 1981
Clinical features of magnesium ‘toxicity’ or ‘intoxication’ at birth (such as apnoea, cyanosis, hypotonia, and/or hyporeflexia)Pre-eclampsia/eclampsia: Brady 1967; Cruz 2009; Lipsitz 1967; Teng 1989
Not clear: Jashi 2014
Microcolon or ‘meconium-plug syndrome’Pre-eclampsia/eclampsia: Amodio 1986; Krasna 1996; Sokal 1972
Nonoliguric hyperkalaemiaPre-eclampsia: Tanaka 2018
Bone abnormalities with prolonged magnesium sulphate for tocolysisTocolysis: Cumming 1989; Kaplan 2006; Kogan 2003; Lamm 1988; Malaeb 2004
Not clear: Ahmad 2013

Clinical features of neonatal hypermagnesemia, magnesium ‘toxicity’, or magnesium ‘intoxication’ at birth were the focus of 5 reports (35 neonates), in which antenatal magnesium sulphate was given for pre-eclampsia/eclampsia (with exposure durations and doses ranging from 3.5 to 46 hours and 11 to 60.4 grams prior to birth, respectively) [202,205,206,213,218], and were variably described throughout the remaining reports. These included low Apgar scores, apnoea, cyanosis, hypotonia, and/or hyporeflexia, with or without the need for active resuscitation and calcium gluconate administration.

Two reports described neonatal death following antenatal magnesium sulphate exposure. In the first report, death was considered to be related to ‘the toxic effects of magnesium on the myocardium’ when given for tocolysis (4-gram IV loading dose followed by 2.5-gram-per-hour IV maintenance dose for approximately 1 day: 51.4 grams total) [204], and in the second, 1 death (of 7) was attributed to ‘overdose’ (unclear dose/regimen) of magnesium sulphate when given for pre-eclampsia/eclampsia [210].

In the context of hypermagnesemia at birth (following exposure to a total of 24 to 28 grams of magnesium sulphate for pre-eclampsia), neonatal gentamicin administration for suspected sepsis was associated with respiratory arrest and cardiac arrest in 2 reports [211,215]. Other specific adverse outcomes attributed to antenatal magnesium sulphate exposure included

  • Microcolon or meconium-plug syndrome (3 reports, 14 neonates, when given for pre-eclampsia/eclampsia: 25 to 41 grams in the day prior to birth in 1 report; regimen not described in 2 reports) [201,209,216];
  • Nonoliguric hyperkalaemia (1 report, 1 neonate, when given for pre-eclampsia: 0.1 gram to 2 grams per hour IV for 12 days) [217];
  • Bone abnormalities (commonly metaphyseal osteopenia, in some cases leading to fracture) (6 reports, 35 neonates, when given for tocolysis: ranging from 1 to 4 grams per hour for between 8 and 13 weeks) [200,203,207,208,212,214].

Discussion

Overall, no clear difference in our primary review outcome, perinatal death, was shown in the randomised trials comparing antenatal magnesium sulphate with placebo/no treatment, nor in regimen comparisons in randomised trials. While 11 of the 138 non-randomised studies reported on perinatal death, only 1 cohort study (at moderate to high risk of bias) observed a possible increased risk of perinatal death, with high-dose (more than 48 grams) antenatal magnesium sulphate exposure for tocolysis [183].

Results for secondary adverse neonatal outcomes were reassuring, with very few clear differences observed between antenatal magnesium sulphate and placebo/no treatment or between different magnesium sulphate regimens. Where possible harms of magnesium sulphate were seen, commonly no confounders were taken into account (and studies were judged to be at high risk of bias), study samples were small (less than 200 babies), and/or differences were observed in (non-formal) subgroup analyses only. Non-randomised studies identified a limited number of outcomes justifying further evaluation, such as from large, high-quality studies (prospective cohorts, individual participant data meta-analyses, or randomised trials of regimen comparisons). These included neonatal death and intestinal morbidity in very preterm neonates with exposure for fetal neuroprotection, patent ductus arteriosus in very preterm or very low birthweight neonates with exposure for pre-eclampsia or tocolysis, and intensive care unit admission in term neonates with exposure for pre-eclampsia. Case reports suggested an association between neonatal bone abnormalities and long-term, high-dose exposure to antenatal magnesium sulphate for tocolysis.

We are not aware of any other published systematic reviews with a focus on potential adverse outcomes for neonates following antenatal magnesium sulphate exposure, though we identified 3 review registrations focused specifically on magnesium sulphate for tocolysis and the outcomes neonatal respiratory depression (CRD42017058912), patent ductus arteriosus (CRD42017060049), and bone abnormalities (CRD42017062550) [18]. Three previous systematic reviews have assessed ‘adverse events’ [13], ‘side effects’ [219], and ‘safety’ [220] for women, and a further systematic review has assessed the effects of antenatal magnesium sulphate specifically on fetal heart rate parameters, finding a small negative effect on rate, variability, and accelerative pattern, ‘not sufficient clinically to warrant medical intervention’ [14].

Our review findings are consistent with those from the relevant Cochrane reviews comparing antenatal magnesium sulphate with placebo/no treatment, or different magnesium sulphate regimens [1,2,4,9,221], though our review includes a wider range of outcomes. As was observed in our review’s tocolysis subgroup for perinatal death, the Cochrane review assessing magnesium sulphate for tocolysis demonstrated a borderline increased risk of fetal, neonatal, or infant death with antenatal magnesium sulphate [9].

A recent non-systematic narrative review evaluated ‘whether antenatal MgSO4 is beneficial or harmful’ in extremely and very preterm neonates [222]. Relevant systematic reviews, meta-analyses, randomised controlled trials, and observational studies were retrieved, with a broad search strategy focused on neuroprotection and cerebral palsy, necrotising enterocolitis, and spontaneous intestinal perforation. The narrative review suggested that current evidence supports the neuroprotective role of antenatal magnesium sulphate for preterm neonates, and that, while the effects are ‘controversial’ and ‘not well established’, a ‘high index of suspicion of gastrointestinal complications in extremely preterms, particularly < 26 weeks of gestation’ is recommended [222]. While our review similarly identified a possibility of harm, the relevant studies were of questionable methodological quality, and our systematic review included additional reports (of higher quality, and involving much larger cohorts) that indicated no increased risk of intestinal morbidity.

The findings of this review are reassuring and can be considered in conjunction with those from relevant reviews demonstrating a clear benefit of antenatal magnesium sulphate [1,2,4], and current international clinical practice guideline recommendations [3,7]. Our review findings of possible adverse outcomes with long-term, high-dose use for tocolysis have implications for settings with continued use for this indication [8] in spite of the absence of benefit shown in systematic reviews and international guidance [7–9].

Strengths and limitations

The main limitations of our review relate to missing data for important outcomes across most studies, the inclusion of published data only, and the heterogeneity of included studies.

Of the 40 randomised trials included in this review, our primary outcome (perinatal death) was reported by 22 (55%); it was reported by only 11 (8%) of the 138 included non-randomised studies. Aside from related mortality outcomes (stillbirth and neonatal death), all other adverse outcomes were reported sparsely, by less than a third of trials, with many outcomes reported by single trials only. While a broader range of adverse neonatal outcomes were reported by the non-randomised studies, apart from neonatal death (50 studies), intraventricular haemorrhage (39 studies), and necrotising enterocolitis (36 studies), all other outcomes were reported by less than a fifth of studies, again, with many reported by single studies only.

In addition to missing data for important outcomes across most studies, a further limitation includes the number of studies with relatively small sample sizes comparing different antenatal magnesium sulphate regimens. Moreover, many studies assessing antenatal magnesium sulphate for relevant indications were not included due to lack of reporting of adverse neonatal outcomes.

We searched extensively across multiple databases and reviewed reference lists for additional reports; however, we did not seek unpublished data. Recent evidence has suggested that while much adverse event information remains unpublished, inclusion of such data generally does not change the direction or statistical significance of pooled risk estimates [223]. While we were not able to fully evaluate non-English publications without available translations for inclusion, we have provided a list of these for readers to consider (S3 Text).

As the aim of the review was to provide a comprehensive, general view of potential unintended adverse outcomes, we designed this review with broad scope [15,16]. This presented challenges, including the number of diverse outcomes, inconsistent reporting, and the vast quantities of heterogeneous data. The study characteristics (including designs, settings, participating women and neonates, and antenatal magnesium sulphate regimens) varied greatly, and reporting was commonly incomplete. The ability to conduct subgroup analyses for the randomised trials was limited, and we did not inappropriately pool data from non-randomised studies. We conducted this review in accordance with recommendations for systematic reviews of adverse events [15–17], and of randomised and non-randomised studies more generally [224]. Our evaluation thus provides a firm basis for any further, narrowly focused studies of specific outcomes and characteristics.

Conclusions

In conclusion, our findings do not support any clear associations between perinatal death or other adverse neonatal outcomes and antenatal magnesium sulphate exposure when given for the beneficial indications of maternal neuroprotection in pre-eclampsia/eclampsia and fetal neuroprotection in cerebral palsy prevention. To further inform safety recommendations of this widely used treatment in pregnancy, future research should be directed towards identified research gaps surrounding specific adverse neonatal outcomes and the impact of particular regimen, pregnancy, and/or birth characteristics.

Supporting information

References

  1. DuleyL, GülmezogluAM, Henderson‐SmartDJ, ChouD. Magnesium sulphate and other anticonvulsants for women with pre‐eclampsia. Cochrane Database Syst Rev. 2010;(11):CD000025 10.1002/14651858.CD000025.pub2 21069663PMC7061250 doi:10.1002/14651858.CD000025.pub2 PubMed
  2. DuleyL, MatarHE, AlmerieMQ, HallDR. Alternative magnesium sulphate regimens for women with pre‐eclampsia and eclampsia. Cochrane Database Syst Rev. 2010;(8):CD007388 10.1002/14651858.CD007388.pub2 20687086PMC8935538 doi:10.1002/14651858.CD007388.pub2 PubMed
  3. World Health Organization. WHO recommendations for prevention and treatment of pre-eclampsia and eclampsia. Geneva: World Health Organization; 2011.23741776 PubMed
  4. DoyleLW, CrowtherCA, MiddletonP, MarretS, RouseD. Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus. Cochrane Database Syst Rev. 2009;(1):CD004661 10.1002/14651858.CD004661.pub3 19160238 doi:10.1002/14651858.CD004661.pub3 PubMed
  5. JayaramPM, MohanMK, FaridI, LindowS. Antenatal magnesium sulfate for fetal neuroprotection: a critical appraisal and systematic review of clinical practice guidelines. J Perinat Med. 2019;47(3):262–9. 10.1515/jpm-2018-0174 30352042 doi:10.1515/jpm-2018-0174 PubMed
  6. MedleyN, PoljakB, MammarellaS, AlfirevicZ. Clinical guidelines for prevention and management of preterm birth: a systematic review. Br J Obstet Gynaecol. 2018;125(11):1361–9.10.1111/1471-0528.1517329460323 doi:10.1111/1471-0528.15173 PubMed
  7. World Health Organization. WHO recommendations on interventions to improve preterm birth outcomes. Geneva: World Health Organization; 2015.26447264 PubMed
  8. ElliottJP, MorrisonJC, BofillJA. Risks and benefits of magnesium sulfate tocolysis in preterm labor (PTL). AIMS Public Health. 2016;3(2):348–56. 10.3934/publichealth.2016.2.348 29546168PMC5690360 doi:10.3934/publichealth.2016.2.348 PubMed
  9. CrowtherCA, BrownJ, McKinlayCJD, MiddletonP. Magnesium sulphate for preventing preterm birth in threatened preterm labour. Cochrane Database Syst Rev. 2014;(8):CD001060 10.1002/14651858.CD001060.pub2 25126773PMC10838393 doi:10.1002/14651858.CD001060.pub2 PubMed
  10. HutchinsonHT, NicholsMM, KuhnCR, VasickaA. Effects of magnesium sulfate on uterine contractility, intrauterine fetus, and infant. Am J Obstet Gynecol. 1964;88:747–58. 10.1016/0002-9378(64)90608-8 14130338 doi:10.1016/0002-9378(64)90608-8 PubMed
  11. TsangRC. Neonatal magnesium disturbances. Am J Dis Child. 1972;124(2):282–93. 10.1001/archpedi.1972.02110140132019 4559534 doi:10.1001/archpedi.1972.02110140132019 PubMed
  12. Van LaeckeS. Hypomagnesemia and hypermagnesemia. Acta Clin Belg. 2019;74(1):41–7. 10.1080/17843286.2018.1516173 30220246 doi:10.1080/17843286.2018.1516173 PubMed
  13. BainES, MiddletonPF, CrowtherCA. Maternal adverse effects of different antenatal magnesium sulphate regimens for improving maternal and infant outcomes: a systematic review. BMC Pregnancy Childbirth. 2013;13:195 10.1186/1471-2393-13-195 24139447PMC4015216 doi:10.1186/1471-2393-13-195 PubMed
  14. NensiA, De SilvaDA, von DadelszenP, SawchuckD, SynnesAR, CraneJ, et al Effect of magnesium sulphate on fetal heart rate parameters: a systematic review. J Obstet Gynaecol Can. 2014;36(12):1055–64. 10.1016/S1701-2163(15)30382-0 25668040 doi:10.1016/S1701-2163(15)30382-0 PubMed
  15. LokeYK, GolderSP, VandenbrouckeJP. Comprehensive evaluations of the adverse effects of drugs: importance of appropriate study selection and data sources. Ther Adv Drug Saf. 2011;2(2):59–68. 10.1177/2042098611401129 25083202PMC4110807 doi:10.1177/2042098611401129 PubMed
  16. LokeYK, PriceD, HerxheimerA. Systematic reviews of adverse effects: framework for a structured approach. BMC Med Res Methodol. 2007;7:32 10.1186/1471-2288-7-32 17615054PMC1933432 doi:10.1186/1471-2288-7-32 PubMed
  17. ZorzelaL, LokeYK, IoannidisJP, GolderS, SantaguidaP, AltmanDG, et al PRISMA harms checklist: improving harms reporting in systematic reviews. BMJ. 2016;352:i157 10.1136/bmj.i157 26830668 doi:10.1136/bmj.i157 PubMed
  18. Centre for Reviews and Dissemination. PROSPERO: international prospective register of systematic reviews. York: Centre for Reviews and Dissemination; 2019 [cited 2019 May 3]. https://www.crd.york.ac.uk/prospero/.
  19. Higgins J, Green S, editors. Cochrane handbook for systematic reviews of interventions. Version 5.1.0 (updated March 2011). Cochrane Collaboration; 2011 [cited 2019 Nov 11]. https://handbook-5-1.cochrane.org/.
  20. ViswanathanM, BerkmanND, DrydenDM, HartlingL. Assessing risk of bias and confounding in observational studies of interventions or exposures: further development of the RTI Item Bank. Rockville (MD): Agency for Healthcare Research and Quality; 2013 8.24006553 PubMed
  21. Nordic Cochrane Centre. Review Manager (RevMan). Version 5.3. Copenhagen: Nordic Cochrane Centre; 2014.
  22. AbdulM, NasirU, KhanN, YusufM. Low-dose magnesium sulphate in the control of eclamptic fits: a randomized controlled trial. Arch Gynecol Obstet. 2013;287(1):43–6. 10.1007/s00404-012-2523-z 22930148 doi:10.1007/s00404-012-2523-z PubMed
  23. AgrawalS, DasV, VermaV, AgarwalA, PandeyA, JainV. Evaluation of medium dose versus standard Pritchard regime of magnesium sulfate in the management of eclampsia in developing nation. Int J Gynaecol Obstet. 2015;131(Suppl 5):E183.
  24. BainE, MiddletonP, YellandL, AshwoodP, CrowtherC. Maternal adverse effects with different loading infusion rates of antenatal magnesium sulphate for preterm fetal neuroprotection: the IRIS randomised trial. Br J Obstet Gynaecol. 2014;121(5):595–603.10.1111/1471-0528.1253524387624 doi:10.1111/1471-0528.12535 PubMed
  25. BegumM, BegumA, QuardirE. Loading dose versus standard regime of magnesium sulfate in the management of eclampsia: a randomized trial. J Obstet Gynaecol Res. 2002;28(3):154–9. 10.1046/j.1341-8076.2002.00029.x 12214831 doi:10.1046/j.1341-8076.2002.00029.x PubMed
  26. BehradB, MoossavifarN, MotahedzadehM, EsmailiH, MoghtadeiiP. A prospective, randomized, controlled trial of high and low doses of magnesium sulfate for acute tocolysis. Acta Med Iran. 2003;41(2):126–31.
  27. BhattacharjeeN, SahaS, GangulyR, PatraK, ShaliB, DasN, et al A randomised comparative study between low-dose intravenous magnesium sulphate and standard intramuscular regimen for the treatment of eclampsia. J Obstet Gynaecol. 2011;31(4):298–303. 10.3109/01443615.2010.549972 21534749 doi:10.3109/01443615.2010.549972 PubMed
  28. BlackwellS, HallakM, HassanS, BerryS, RussellE, SorokinY. The effects of intrapartum magnesium sulfate therapy on fetal serum interleukin-1β, interleukin-6, and tumor necrosis factor-α at delivery: a randomized, placebo-controlled trial. Am J Obstet Gynecol. 2001;184(7):1320–4. 10.1067/mob.2001.115745 11408847 doi:10.1067/mob.2001.115745 PubMed
  29. ChamaC, GeidamA, BakoB, MairigaA, AtterwahmieA. A shortened versus standard matched postpartum magnesium sulphate regimen in the treatment of eclampsia: a randomised controlled trial. Afr J Reprod Health. 2013; 17(3):131–6. 24069775 PubMed
  30. ChenF-P, ChangS-D, ChuK-K. Expectant management in severe preeclampsia: does magnesium sulfate prevent the development of eclampsia? Acta Obstet Gynecol Scand. 1995;74(3):182–5.10.3109/000163495090089357900522 doi:10.3109/00016349509008935 PubMed
  31. ChissellS, BothaJ, MoodleyJ, McFadyenL. Intravenous and intramuscular magnesium sulphate regimens in severe pre-eclampsia. S Afr Med J. 1994;84(9):607–10. 7839282 PubMed
  32. CoetzeeE, DommisseJ, AnthonyJ. A randomised controlled trial of intravenous magnesium sulphate versus placebo in the management of women with severe pre-eclampsia. Br J Obstet Gynaecol. 1998;105(3):300–3. 10.1111/j.1471-0528.1998.tb10090.x 9532990 doi:10.1111/j.1471-0528.1998.tb10090.x PubMed
  33. ColonI, BerlettiM, GarabedianM, WilcoxN, WilliamsK, ChuehJ, et al Randomized, double-blinded trial of magnesium sulfate tocolysis vs intravenous normal saline for nonsevere placental abruption. Am J Obstet Gynecol. 2015;212(1 Suppl):S388–9.10.1055/s-0036-157132426871905 doi:10.1055/s-0036-1571324 PubMed
  34. CottonD, StrassnerH, HillL, SchifrinB, PaulR. Comparison of magnesium sulfate, terbutaline and a placebo for inhibition of preterm labor. A randomized study. J Reprod Med. 1984;29(2):92–7. 6708033 PubMed
  35. CoxS, ShermanL, LevenoK. Randomized investigation of magnesium sulfate for prevention of preterm birth. Am J Obstet Gynecol. 1990;163(3):767–72. 10.1016/0002-9378(90)91065-k 2206069 doi:10.1016/0002-9378(90)91065-k PubMed
  36. CrowtherC, HillerJ, DoyleL, HaslamR, Australasian Collaborative Trial of Magnesium Sulphate (ACTOMgSO4) Collaborative Group. Effect of magnesium sulfate given for neuroprotection before preterm birth. A randomized controlled trial. JAMA. 2003;290(20):2669–76. 10.1001/jama.290.20.2669 14645308 doi:10.1001/jama.290.20.2669 PubMed
  37. EasterlingT, HebertM, BrackenH, DarwishE, RamadanMC, ShaarawyS, et al A randomized trial comparing the pharmacology of magnesium sulfate when used to treat severe preeclampsia with serial intravenous boluses versus a continuous intravenous infusion. BMC Pregnancy Childbirth. 2018;18(1):290 10.1186/s12884-018-1919-6 29976161PMC6034206 doi:10.1186/s12884-018-1919-6 PubMed
  38. FoxM, AllbertJ, McCaulJ, MartinR, McLaughlinB, MorrisonJ. Neonatal morbidity between 34 and 37 weeks’ gestation. Obstet Gynecol Surv. 1993;49(4):242–3.8263618 PubMed
  39. Magpie Trial Collaborative Group. Do women with pre-eclampsia, and their babies, benefit from magnesium sulphate? The Magpie Trial: a randomised placebo-controlled trial. Lancet. 2002;359(1):1877–90.1205754910.1016/s0140-6736(02)08778-0 doi:10.1016/s0140-6736(02)08778-0 PubMed
  40. HowHY CC, CookVD, MilesDE, SpinnatoJA. Preterm premature rupture of membranes: aggressive tocolysis versus expectant management. J Matern Fetal Med. 1998;7(1):8–12. 10.1002/(SICI)1520-6661(199801/02)7:1<8::AID-MFM2>3.0.CO;2-S 9502662 doi:10.1002/(SICI)1520-6661(199801/02)7:1<8::AID-MFM2>3.0.CO;2-S PubMed
  41. KeepanasserilA, MauryaDK, ManikandanK, SuriyaYJ, HabeebullahS, RaghavanSS. Prophylactic magnesium sulphate in prevention of eclampsia in women with severe preeclampsia: randomised controlled trial (PIPES trial). J Obstet Gynaecol. 2018;38(3):305–9. 10.1080/01443615.2017.1351931 28974124 doi:10.1080/01443615.2017.1351931 PubMed
  42. LewisDF, BergstedtS, EdwardsMS, BurlisonS, GallaspyJW, BrooksGG, AdairCD. Successful magnesium sulfate tocolysis: is “weaning” the drug necessary? Am J Obstet Gynecol. 1997;177(4):742–5. 10.1016/s0002-9378(97)70261-8 9369812 doi:10.1016/s0002-9378(97)70261-8 PubMed
  43. LivingstonJ, LivingstonL, RamseyR, MabieB, SibaiB. Magnesium sulfate in women with mild preeclampsia: a randomized controlled trial. Obstet Gynecol. 2003;101(2):217–20. 10.1016/s0029-7844(02)03053-3 12576241 doi:10.1016/s0029-7844(02)03053-3 PubMed
  44. MalapakaS, BallalP. Low-dose magnesium sulfate versus Pritchard regimen for the treatment of eclampsia and imminent eclampsia. Int J Gynaecol Obstet. 2011;115(1):70–2. 10.1016/j.ijgo.2011.05.013 21798536 doi:10.1016/j.ijgo.2011.05.013 PubMed
  45. MarretS, MarpeauL, Zupan-SimunekV, EurinD, LevequeC, HellotM-F, et al Magnesium sulphate given before very-preterm birth to protect infant brain: the randomised controlled PREMAG trial. Br J Obstet Gynaecol. 2007;114(3):310–8.10.1111/j.1471-0528.2006.01162.x17169012 doi:10.1111/j.1471-0528.2006.01162.x PubMed
  46. MirzamoradiM, BehnamM, JahedT, Saleh-GargariS. Does magnesium sulfate delay the active phase of labor in women with premature rupture of membranes? A randomized controlled trial. Taiwan J Obstet Gynecol. 2014;53(3):309–12. 10.1016/j.tjog.2013.06.014 25286782 doi:10.1016/j.tjog.2013.06.014 PubMed
  47. MittendorfR, DambrosiaJ, PrydeP, LeeK-S, GianopouloisJ, BesingerR, et al Association between the use of antenatal magnesium sulfate in preterm labor and adverse health outcomes in infants. Am J Obstet Gynecol. 2002;186(6):1111–8. 10.1067/mob.2002.123544 12066082 doi:10.1067/mob.2002.123544 PubMed
  48. MoodleyJ, MoodleyV. Prophylactic anticonvulsant therapy in hypertensive crises of pregnancy—the need for a large, randomized trial. Hypertens Pregnancy. 1994;13(3):245–52.
  49. MundleS, RegiA, EasterlingT, BiswasB, BrackenH, KhedekarV, et al Treatment approaches for preeclampsia in low-resource settings: a randomized trial of the Springfusor pump for delivery of magnesium sulfate. Pregnancy Hypertens. 2012;2(1):32–8. 10.1016/j.preghy.2011.09.002 26104987 doi:10.1016/j.preghy.2011.09.002 PubMed
  50. OrjiE, OgokeG, FasubaaO. Efficacy of a single loading dose of magnesium sulphate versus the standard Pritchard regimen in the management of severe preeclampsia in an African population. Int J Gynaecol Obstet. 2012;119(S3):S447.
  51. ParashiS, BordbarA, MahmoodiY, JafariM. The survey of magnesium sulfate in prevention of intraventricular haemorrhage in premature infants: a randomized clinical trial. Shiraz E Med J. 2017;18(11):e55094.
  52. PascoalACF, KatzL, PintoMH, SantosCA, BragaLCO, MaiaSB, et al Serum magnesium levels during magnesium sulfate infusion at 1 gram/hour versus 2 grams/hour as a maintenance dose to prevent eclampsia in women with severe preeclampsia: a randomized clinical trial. Medicine (Baltimore). 2019;98(32):e16779.3139340210.1097/MD.0000000000016779PMC6709127 doi:10.1097/MD.0000000000016779 PubMed
  53. RimalS, RijalP, BhattR, ThapaK. Loading dose only versus standard dose magnesium sulfate seizure prophylaxis in severe pre-eclamptic women. J Nepal Med Assoc. 2017;56(208):388–94.29453467 PubMed
  54. RouseD, HirtzD, ThomE, VarnerM, SpongC, MercerB, et al A randomized, controlled trial of magnesium sulfate for the prevention of cerebral palsy. N Engl J Med. 2008;359(9):895–905. 10.1056/NEJMoa0801187 18753646PMC2803083 doi:10.1056/NEJMoa0801187 PubMed
  55. SahaP, KaurJ, GoelP, KatariaS, TandonR, SahaL. Safety and efficacy of low dose intramuscular magnesium sulphate (MgSO4) compared to intravenous regimen for treatment of eclampsia J Obstet Gynaecol Res. 2017;4(10):1543–9.10.1111/jog.1342428714170 doi:10.1111/jog.13424 PubMed
  56. Shilva, SahaS, KalraJ, PrasadR. Safety and efficacy of low-dose MgSO4 in the treatment of eclampsia. Int J Gynaecol Obstet. 2007;97(2):150–1. 10.1016/j.ijgo.2007.01.008 17368649 doi:10.1016/j.ijgo.2007.01.008 PubMed
  57. ShreyaM, KrishnaL, ShailajaN, BhatB. Evaluation of single dose magnesium sulphate and Pritchard regimen in the treatment of eclampsia—a comparative study. Biomedicine. 2014;34(2):252–6.
  58. SinghS, BeheraA. Eclampsia in Eastern India: incidence, demographic profile and response to three different anticonvulsant regimes of magnesium sulphate. Internet J Gynecol Obstet. 2011;15(2):1–7.
  59. TangmanowutthikulS, ChampawongR, SongthamwatS, SongthamwatM. Comparison of magnesium sulphate protocols by weight-adjusted versus two grams per hour for preventing convulsion in preeclampsia: a randomised controlled trial. J Clin Diagn Res. 2019;13(2):QC01–4.
  60. TerroneD, RinehartB, KimmelE, MayW, LarmonJ, MorrisonJ. A prospective, randomized, controlled trial of high and low maintenance doses of magnesium sulfate for acute tocolysis. Am J Obstet Gynecol. 2000;182(6):1477–82. 10.1067/mob.2000.107334 10871468 doi:10.1067/mob.2000.107334 PubMed
  61. WiltlinA, FriedmanS, SibaiB. The effect of magnesium sulfate therapy on the duration of labor in women with mild preeclampsia at term: a randomized, double-blind, placebo-controlled trial. Am J Obstet Gynecol. 1997;176(3):623–7. 10.1016/s0002-9378(97)70558-1 9077617 doi:10.1016/s0002-9378(97)70558-1 PubMed
  62. Adama-HondeglaAB, Lawson-EviK, BassowaA, ModjiS, EgblaKF, AkpadzaK. Perinatal mortality risk factors of infants bom from eclamptic mothers at Tokoin Teaching Hospital of Lome. Pak J Med Sci. 2013;13(5):391–5.
  63. AlexanderJM, McIntireDD, LevenoKJ, CunninghamFG. Selective magnesium sulfate prophylaxis for the prevention of eclampsia in women with gestational hypertension. Obstet Gynecol. 2006;108(4):826–32. 10.1097/01.AOG.0000235721.88349.80 17012442 doi:10.1097/01.AOG.0000235721.88349.80 PubMed
  64. AlstonMJ, AlexandrovicK, StiglichN, MetzTD. Discontinuation of tocolytics for preterm labor in an academic safety net hospital: impact on the duration of betamethasone exposure. J Reprod Med. 2016;61(2):109–13.27172632 PubMed
  65. AmbadkarA, PrasadM, ChauhanAR. Neonatal effects of maternal magnesium sulphate in late preterm and term pregnancies. J Obstet Gynaecol India. 2019;69(1):25–30. 10.1007/s13224-017-1074-4 30814806PMC6361188 doi:10.1007/s13224-017-1074-4 PubMed
  66. BajajM, NatarajanG, ShankaranS, WyckoffM, LaptookAR, BellEF, et al Delivery room resuscitation and short-term outcomes in moderately preterm infants. J Pediatr. 2018;195:33–8e2. 10.1016/j.jpeds.2017.11.039 29306493PMC5869086 doi:10.1016/j.jpeds.2017.11.039 PubMed
  67. BasuSK, ChickajajurV, LopezV, BhutadaA, PagalaM, RastogiS. Immediate clinical outcomes in preterm neonates receiving antenatal magnesium for neuroprotection. J Perinat Med. 2012;40(2):185–9.10.1515/JPM.2011.09421834608 doi:10.1515/JPM.2011.094 PubMed
  68. BeldenMK, GnadtS, EbertA. Effects of maternal magnesium sulfate treatment on neonatal feeding tolerance. J Pediatri Pharmacol Ther. 2017;22(2):112–7.10.5863/1551-6776-22.2.112PMC541085928469536 doi:10.5863/1551-6776-22.2.112 PubMed
  69. Bertello GreccoM, BarrónB, RigoD, McCormick CookA, Pajón ScoccoJ, NovoaP, et al Maternal and neonatal safety with the use of magnesium sulfate in preeclampsia. Kidney Int Rep. 2019;4(7):S146.
  70. BlackB, Holditch-DavisD, SchwartzT, ScherMS. Effects of antenatal magnesium sulfate and corticosteroid therapy on sleep states of preterm infants. Res Nurs Health. 2006;29(4):269–80. 10.1002/nur.20141 16847907 doi:10.1002/nur.20141 PubMed
  71. BlackwellSC, RedmanME, WhittyJE, RefuerzoJS, BerrySM, SorokinY, et al The effect of intrapartum magnesium sulfate therapy on fetal cardiac troponin I levels at delivery. J Matern Fetal Neonatal Med. 2002;12(5):327–31. 10.1080/jmf.12.5.327.331 12607765 doi:10.1080/jmf.12.5.327.331 PubMed
  72. BontaBW, ChinTK, DeVoeWM. Maternal intravenous MgSO4 administration and its effects on neonatal respiratory function and risk of development of hemodynamically significant patent ductus arteriosus shunts during the initial 72 hours of life. J Investig Med. 2000;48(1):107A.
  73. BoyleA, GreerK, CaballeroA, NortonT, KateP, FergusonJ, et al Neonatal outcomes in obese women undergoing cesarean delivery for fetal heart rate tracing abnormalities. Am J Obstet Gynecol. 2018;218(1):S335.
  74. BozkurtO, ErasZ, CanpolatFE, OguzSS, UrasN, DilmenU. Antenatal magnesium sulfate and neurodevelopmental outcome of preterm infants born to preeclamptic mothers. J Matern Fetal Neonatal Med. 2016;29(7):1101–4. 10.3109/14767058.2015.1035641 25893546 doi:10.3109/14767058.2015.1035641 PubMed
  75. BrazyJE, GrimmJK, LittleVA. Neonatal manifestations of severe maternal hypertension occurring before the thirty-sixth week of pregnancy. J Pediatr. 1982;100(2):265–71. 10.1016/s0022-3476(82)80653-7 7057337 doi:10.1016/s0022-3476(82)80653-7 PubMed
  76. BrookfieldK, SuF, DroverD, AdelusM, LyellD, CarvalhoB. Umbilical cord magnesium levels and neonatal resuscitation in infants exposed to magnesium sulfate. Am J Obstet Gynecol. 2015;212(1 Suppl):S395–6.
  77. BrookfieldK, O’MalleyK, Yeaton-MasseyA, ButwickA. Does magnesium sulfate exposure attenuate the effete of steroids administered for fetal lung maturation? Am J Obstet Gynecol. 2016;1(Suppl):S89.
  78. BrownBE, VincerM, AcottP, El-NaggarW, O’ConnellC, KajetanowiczA. Systemic hypertension in preterm infants—a population-based study. Paediatr Child Health. 2019;24(Suppl 2):e47–8.
  79. CanterinoJC, VermaUL, VisintainerPF, FigueroaR, KleinSA, TejaniNA. Maternal magnesium sulfate and the development of neonatal periventricular leucomalacia and intraventricular hemorrhage. Obstet Gynecol. 1999;93(3):396–402. 10.1016/s0029-7844(98)00455-4 10074987 doi:10.1016/s0029-7844(98)00455-4 PubMed
  80. CawyerCR. The association of magnesium sulfate with maternal morbidity when used for preeclampsia without severe features. Am J Obstet Gynecol. 2019;220(1):S292–3.
  81. ChoGJ, LeeJE, HongHR, HongSC, HongYS, KimHJ, et al Maternal magnesium sulfate treatment is not associated with serum calcium levels of preterm neonate. Am J Obstet Gynecol. 2014;210(1 Suppl):S356.
  82. ChowdhuryJR, ChaudhuriS, BhattacharyyaN, BiswasPK, PanpaliaM. Comparison of intramuscular magnesium sulfate with low dose intravenous magnesium sulfate regimen for treatment of eclampsia. J Obstet Gynaecol Res. 2009;35(1):119–25. 10.1111/j.1447-0756.2008.00842.x 19215558 doi:10.1111/j.1447-0756.2008.00842.x PubMed
  83. ChunE-H, DoS-H, ShinH-J, NaH-S, HwangJ-W. Effects of magnesium sulfate on the labor duration and neonatal outcome in parturients with preeclampsia. Anesth Pain Med. 2014;9(2):128–33.
  84. CuffRD, SullivanSA, ChangEY. Impact of dosing schedule on uptake of neuroprotective magnesium sulfate. J Matern Fetal Neonatal Med. 2018 9 19 10.1080/14767058.2018.1513482 30122071 doi:10.1080/14767058.2018.1513482 PubMed
  85. DasM, ChaudhuriPR, MondalBC, MitraS, BandyopadhyayD, PramanikS. Assessment of serum magnesium levels and its outcome in neonates of eclamptic mothers treated with low-dose magnesium sulfate regimen. Indian J Pharmacol. 2015;47(5):502–8. 10.4103/0253-7613.165183 26600638PMC4621670 doi:10.4103/0253-7613.165183 PubMed
  86. De JesusL, SoodB, ShankaranS, KendrickD, DasA, BellE, et al Antenatal magnesium sulfate exposure and acute cardiorespiratory events in preterm infants. Am J Obstet Gynecol. 2015;212(1):94.e1–7.2504680610.1016/j.ajog.2014.07.023PMC4275326 doi:10.1016/j.ajog.2014.07.023 PubMed
  87. De SilvaD, SynnesA, von DadelszenP, LeeT, BoneJ, Mag-CP, et al MAGnesium sulphate for fetal neuroprotection to prevent Cerebral Palsy (MAG-CP)—implementation of a national guideline in Canada. Implement Sci. 2018;13(1):8 10.1186/s13012-017-0702-9 29325592PMC5765609 doi:10.1186/s13012-017-0702-9 PubMed
  88. de VecianaM, PortoM, MajorCA, BarkeJI. Tocolysis in advanced preterm labor: impact on neonatal outcome. Am J Perinatol. 1995;12(4):294–8. 10.1055/s-2007-994478 7575840 doi:10.1055/s-2007-994478 PubMed
  89. DeeringSH, StaggAR, SpongCY, AbubakarK, PezzulloJC, GhidiniA. Antenatal magnesium treatment and neonatal illness severity as measured by the Score for Neonatal Acute Physiology (SNAP). J Matern Fetal Neonatal Med. 2005;17(2):151–5. 10.1080/14767050500043145 16076625 doi:10.1080/14767050500043145 PubMed
  90. del MoralT, Gonzalez-QuinteroVH, ClaureN, VanbuskirkS, BancalariE. Antenatal exposure to magnesium sulfate and the incidence of patent ductus arteriosus in extremely low birth weight infants. J Perinatol. 2007;27(3):154–7. 10.1038/sj.jp.7211663 17314984 doi:10.1038/sj.jp.7211663 PubMed
  91. delValleGM, BisterGL, LynchLA, CummingsJJ. Prenatal magnesium sulfate exposure and the incidence of cerebral palsy in very low birth weight infants. J Investig Med. 1998;46(1):175A.
  92. DerksJB, SolCM, Van LeeuwenJ, KeunenK, MulderEJ, De VriesLS, et al Antenatal magnesium sulphate for neuroprotection reduces punctate white matter lesions at 30 weeks MRI in the human neonate. Reprod Sci. 2016;23(Suppl 1):273A.
  93. DowneyLC, CottenCM, HornikCP, LaughonMM, ToliaVN, ClarkRH, et al Association of in utero magnesium exposure and spontaneous intestinal perforations in extremely low birth weight infants. J Perinatol. 2017;37(6):641–4. 10.1038/jp.2016.274 28125094PMC5446291 doi:10.1038/jp.2016.274 PubMed
  94. DrassinowerD, ObicanS, LevinH, Gyamfi-BannermanC. Immediate neonatal outcomes in infants exposed to magnesium sulfate at the time of delivery. Am J Obstet Gynecol. 2015;212(1 Suppl):S90.
  95. DuffyCR, OdiboAO, RoehlKA, MaconesGA, CahillAG. Effect of magnesium sulfate on fetal heart rate patterns in the second stage of labor. Obstet Gynecol. 2012;119(6):1129–36. 10.1097/AOG.0b013e318257181e 22617576 doi:10.1097/AOG.0b013e318257181e PubMed
  96. EdwardsJ, EdwardsL, SwamyG, GrotegutC. Magnesium sulfate for neuroprotection in the setting of chorioamnionitis. J Matern Fetal Neonatal Med. 2018;31(9):1156–60. 10.1080/14767058.2017.1311312 28395549 doi:10.1080/14767058.2017.1311312 PubMed
  97. ElimianA, VermaR, OgburnP, WiencekV, SpitzerA, QuirkJG. Magnesium sulfate and neonatal outcomes of preterm neonates. J Matern Fetal Neonatal Med. 2002;12(2):118–22. 10.1080/jmf.12.2.118.122 12420842 doi:10.1080/jmf.12.2.118.122 PubMed
  98. ElliottJ, GariteT, ClarkR, CombsA. Perinatal effect of magnesium sulfate administered for tocolysis. Am J Obstet Gynecol. 2003;189(6 Suppl):S63.
  99. FarkouhLJ, ThorpJA, JonesPG, ClarkRH, KnoxGE. Antenatal magnesium exposure and neonatal demise. Am J Obstet Gynecol. 2001;185(4):869–72. 10.1067/mob.2001.117362 11641668 doi:10.1067/mob.2001.117362 PubMed
  100. FineSmithRB, RocheK, YellinPB, WalshKK, ShenC, ZeglisM, et al Effect of magnesium sulfate on the development of cystic periventricular leukomalacia in preterm infants. Am J Perinatol. 1997;14(5):303–7. 10.1055/s-2007-994149 9259949 doi:10.1055/s-2007-994149 PubMed
  101. GanoD, HoML, PartridgeJC, GlassHC, XuD, BarkovichAJ, et al Antenatal exposure to magnesium sulfate is associated with reduced cerebellar hemorrhage in preterm newborns. J Pediatr. 2016;178:68–74. 10.1016/j.jpeds.2016.06.053 27453378PMC5085851 doi:10.1016/j.jpeds.2016.06.053 PubMed
  102. Garcia AlonsoL, Pumarada PrietM, Gonzalez ColmeneroE, Concheiro GuisanA, Suarez AlboM, Duran Fernandez-FeijooC, et al Prenatal therapy with magnesium sulfate and its correlation with neonatal serum magnesium concentration. Am J Perinatol. 2018;35(2):170–6. 10.1055/s-0037-1606358 28854447 doi:10.1055/s-0037-1606358 PubMed
  103. GasparyanA. [Neurosonographical characteristics of dysmature infants depending on conducted neuroprotection.] Georgian Med News. 2017;(268–9):72–5.28820417 PubMed
  104. GhidiniA, EspadaRA, SpongCY. Does exposure to magnesium sulfate in utero decrease the risk of necrotizing enterocolitis in premature infants? Acta Obstet Gynecol Scand. 2001;80(2):126–9. 11167206 PubMed
  105. GibbinsKJ, BrowningKR, LopesVV, AndersonBL, RouseDJ. Evaluation of the clinical use of magnesium sulfate for cerebral palsy prevention. Obstet Gynecol. 2013;121(2 Pt 1):235–40. 10.1097/AOG.0b013e31827c5cf8 23344271 doi:10.1097/AOG.0b013e31827c5cf8 PubMed
  106. GirsenAI, GreenbergMB, El-SayedYY, LeeH, CarvalhoB, LyellDJ. Magnesium sulfate exposure and neonatal intensive care unit admission at term. J Perinatol. 2015;35(3):181–5. 10.1038/jp.2014.184 25321647 doi:10.1038/jp.2014.184 PubMed
  107. Gonzalez-QuinteroVH, TolaymatL, ClaureN, VanbuskirkS, SimanD, del MoralT, et al Survival rate in neonates exposed to magnesium sulfate. J Perinat Med. 2001;29(Suppl 1):20.
  108. GreenbergMB, PennAA, ThomasLJ, El-SayedYY, CaugheyAB, LyellDJ. Neonatal medical admission in a term and late-preterm cohort exposed to magnesium sulfate. Am J Obstet Gynecol. 2011;204(6):515.e1–7.2137630210.1016/j.ajog.2011.01.046 doi:10.1016/j.ajog.2011.01.046 PubMed
  109. GreenbergMB, PennAA, WhitakerKR, KogutEA, El-SayedYY, CaugheyAB, et al Effect of magnesium sulfate exposure on term neonates. J Perinatol. 2013;33(3):188–93. 10.1038/jp.2012.95 22836873 doi:10.1038/jp.2012.95 PubMed
  110. GretherJK, HoogstrateJ, SelvinS, NelsonKB. Magnesium sulfate tocolysis and risk of neonatal death. Am J Obstet Gynecol. 1998;178(1 Pt 1):1–6. 10.1016/s0002-9378(98)70617-9 9465794 doi:10.1016/s0002-9378(98)70617-9 PubMed
  111. GrimblyC, RosolowskyE, AzizK, O’ReillyM, CheungPY, SchmolzerG. New baby jitters: novel characterization of the incidence and risk factors for neonatal hypoglycemia in the premature infant <33 weeks. Paediatr Child Health. 2015;20(5):e86.
  112. GulcanH, GungorS, TikerF, KilicdagH. Effect of perinatal factors on time of first stool passage in preterm newborns: an open, prospective study. Curr Ther Res Clin Exp. 2006;67(3):214–25. 10.1016/j.curtheres.2006.06.002 24678097PMC3966019 doi:10.1016/j.curtheres.2006.06.002 PubMed
  113. GursoyT, ImamogluEY, OvaliF, KaratekinG. Effects of antenatal magnesium exposure on intestinal blood flow and outcome in preterm neonates. Am J Perinatol. 2015;32(11):1064–9. 10.1055/s-0035-1548541 25825964 doi:10.1055/s-0035-1548541 PubMed
  114. HavranekT, AshmeadeTL, AfanadorM, CarverJD. Effects of maternal magnesium sulfate administration on intestinal blood flow velocity in preterm neonates. Neonatology. 2011;100(1):44–9. 10.1159/000319049 21212694 doi:10.1159/000319049 PubMed
  115. HechtmanJ, BlackwellS, MoldenhauerJ, RefuerzoJ, HassanS, BerryS, et al Lack of association of neonatal mortality and exposure to tocolytic magnesium. Am J Obstet Gynecol. 2002;187(6 Suppl 1):S124.
  116. HolcombWL, ShackelfordGD, PetrieRH. Magnesium tocolysis and neonatal bone abnormalities: a controlled study. Obstet Gynecol. 1991;78(4):611–4. 1923163 PubMed
  117. HomK, BrarB, KennelP, JacksonD. Magnesium for fetal neuroprotection: should it be started when delivery is not imminent in pprom? Obstet Gynecol. 2018;131(Suppl 1):44S.
  118. HongJY, KimY-M, HongJY, SeoM-r, ChaeJ, SungJ-H, et al Does antenatal magnesium sulfate exposure increase the risk of necrotizing enterocolitis in preterm neonates? Am J Obstet Gynecol. 2019;220(1):S327.
  119. IgarashiH, HonmaY, SuwaK, MomoiM, YanagisawaM. The clinical effects of hypermagnesemia on preterm infants of mothers treated with magnesium sulfate for tocolysis. Acta Neonatol Japon. 1995;31(2):388–93.
  120. ImamogluEY, GursoyT, KaratekinG, OvaliF. Effects of antenatal magnesium sulfate treatment on cerebral blood flow velocities in preterm neonates. J Perinatol. 2014;34(3):192–6. 10.1038/jp.2013.182 24480905 doi:10.1038/jp.2013.182 PubMed
  121. JamesAT, CorcoranJD, HayesB, FranklinO, El-KhuffashA. The effect of antenatal magnesium sulfate on left ventricular afterload and myocardial function measured using deformation and rotational mechanics imaging. J Perinatol. 2015;35(11):913–8. 10.1038/jp.2015.104 26291779 doi:10.1038/jp.2015.104 PubMed
  122. JazayeriA, JazayeriMK, SutkinG. Tocolysis does not improve neonatal outcome in patients with preterm rupture of membranes. Am J Perinatol. 2003;20(4):189–93. 10.1055/s-2003-40606 12874729 doi:10.1055/s-2003-40606 PubMed
  123. JeanneteauP, BouetPE, BaissonAL, CourtayV, Gascoin-LachambreG, GillardP, et al Evaluation of the clinical use of magnesium sulfate for cerebral palsy prevention. J Matern Fetal Neonatal Med. 2014;27(Suppl 1):377–8.
  124. JonesCW, PetrashekK, WenzlaffM, SimpsonP, PanAY. Prenatal magnesium sulfate and time to first stool in late preterm infants. Obstet Gynecol. 2018;131(Suppl 1):160S.
  125. JungEJ, ByunJM, KimYN, LeeKB, SungMS, KimKT, et al Antenatal magnesium sulfate for both tocolysis and fetal neuroprotection in premature rupture of the membranes before 32 weeks’ gestation. J Matern Fetal Neonatal Med. 2018;31(11):1431–41. 10.1080/14767058.2017.1317743 28391733 doi:10.1080/14767058.2017.1317743 PubMed
  126. KamilyaG, BharracharyyaSK, MukherjiJ. Changing trends in the management of eclampsia from a teaching hospital. J Indian Med Assoc. 2005;103(3):132,134–5.16173289 PubMed
  127. KamyarM, BardsleyT, KorgenskiK, ClarkE. Magnesium sulfate and the extremely low birth weight neonate. Am J Obstet Gynecol. 2015;212(1 Suppl):S362–3.
  128. KamyarM, BardsleyT, KorgenskiK, ClarkEAS. Association of antenatal magnesium sulfate with neonatal morbidity and mortality in very preterm infants. Reprod Sci. 2015;22(Suppl 1):144A.
  129. KamyarM, ClarkEA, YoderBA, VarnerMW, ManuckTA. Antenatal magnesium sulfate, necrotizing enterocolitis, and death among neonates<28 weeks gestation. AJP Rep. 2016;6(1):e148–54. 10.1055/s-0036-1581059 27054046PMC4816636 doi:10.1055/s-0036-1581059 PubMed
  130. KamyarM, ManuckTA, StoddardGJ, VarnerMW, ClarkEAS. Magnesium sulfate, chorioamnionitis, and neurodevelopment after preterm birth. Br J Obstet Gynaecol. 2016;123(7):1161–6.10.1111/1471-0528.1346026036660 doi:10.1111/1471-0528.13460 PubMed
  131. KamyarM, VarnerM, ClarkE. Magnesium sulfate neuroprophylaxis and the effect of infant sex. Am J Obstet Gynecol. 2015;212(1 Suppl):S144.
  132. KatayamaY, MinamiH, EnomotoM, TakanoT, HayashiS, LeeYK. Antenatal magnesium sulfate and the postnatal response of the ductus arteriosus to indomethacin in extremely preterm neonates. J Perinatol. 2011;31(1):21–4. 10.1038/jp.2010.62 20505743 doi:10.1038/jp.2010.62 PubMed
  133. KellyMJ, ViscardiRM. Effects of maternal magnesium sulfate on preterm newborns. Pediatr Res. 1992;31(4 Pt 2):207A.1313958
  134. KhodapanahandehF, KhosraviN, LarijaniT. Risk factors for intraventricular hemorrhage in very low birth weight infants in Tehran, Iran. Turk J Pediatr. 2008;50(3):247–52. 18773670 PubMed
  135. KimberlinDF, HauthJC, GoldenbergRL, BottomsSF, IamsJD, MercerB, et al The effect of maternal magnesium sulfate treatment on neonatal morbidity in < or = 1000-gram infants. Am J Perinatol. 1998;15(11):635–41. 10.1055/s-2007-994082 10064205 doi:10.1055/s-2007-994082 PubMed
  136. KoksalN, BaytanB, BayramY, NacarkucukE. Risk factors for intraventricular haemorrhage in very low birth weight infants. Indian J Pediatr. 2002;69(7):561–4. 10.1007/bf02722677 12173693 doi:10.1007/bf02722677 PubMed
  137. KubanKC, LevitonA, PaganoM, FentonT, StrassfeldR, WolffM. Maternal toxemia is associated with reduced incidence of germinal matrix hemorrhage in premature babies. J Child Neurol. 1992;7(1):70–6. 10.1177/088307389200700113 1552156 doi:10.1177/088307389200700113 PubMed
  138. LaiTC, LiaoCY. Maternal magnesium sulfate treatment and infant outcomes. J Obstet Gynaecol Res. 2017;43(Suppl 1):56–7.
  139. LeeB, ChoGJ, JinHM, ChungSH, OhMJ, KimHJ. Maternal magnesium sulfate treatment is not associated with serum calcium levels of preterm neonate. J Perinat Med. 2015;43:667.25294714
  140. LeeNY, ChoSJ, ParkEA. Influence of antenatal magnesium sulfate exposure on perinatal outcomes in VLBW infants with maternal preeclampsia. Neonatal Med. 2013;20(1):28–34.
  141. LeungJC, CifraCL, AgtheAG, SunCC, ViscardiRM. Antenatal factors modulate hearing screen failure risk in preterm infants. Arch Dis Child Fetal Neonatal Ed. 2016;101(1):F56–61. 10.1136/archdischild-2014-307843 26195624 doi:10.1136/archdischild-2014-307843 PubMed
  142. LevitonA, PanethN, SusserM, ReussML, AllredEN, KubanK, et al Maternal receipt of magnesium sulfate does not seem to reduce the risk of neonatal white matter damage. Pediatrics. 1997;99(4):E2 10.1542/peds.99.4.e2 9099777 doi:10.1542/peds.99.4.e2 PubMed
  143. LipsitzPJ. The clinical and biochemical effects of excess magnesium in the newborn. Pediatrics. 1971;47(3):501–9. 5547870 PubMed
  144. Lloreda-GarciaJM, Lorente-NicolásA, Bermejo-CostaF, Martínez-UriarteJ, López-PérezR. Necesidad de reanimación en prematuros menores de 32 semanas expuestos a sulfato de magnesio para neuroprotección fetal. Rev Chil Pediatr. 2016;87(4):261–7.2677800810.1016/j.rchipe.2015.11.006 doi:10.1016/j.rchipe.2015.11.006 PubMed
  145. MartinD, GonzalezJL, GardnerMO, IzquierdoLA, TobeyK, CuretLB. Incidence of intraventricular hemorrhage in neonates under 32 weeks of gestation delivered to mothers with severe pre-eclampsia. Prenat Neonatal Med. 1998;3(2):250–4.
  146. MatsudaY, MaedaY, ItoM, SakamotoH, MasaokaN, TakadaM, et al Effect of magnesium sulfate treatment on neonatal bone abnormalities. Gynecol Obstet Invest. 1997;44(2):82–8. 10.1159/000291492 9286718 doi:10.1159/000291492 PubMed
  147. McGuinnessGA, WeinsteinMM, CruikshankDP, PitkinRM. Effects of magnesium sulfate treatment on perinatal calcium metabolism. II. Neonatal responses. Obstet Gynecol. 1980;56(5):595–600. 7432730 PubMed
  148. McPhersonJA, RouseDJ, GrobmanWA, PalatnikA, StamilioDM. Association of duration of neuroprotective magnesium sulfate infusion with neonatal and maternal outcomes. Obstet Gynecol. 2014;124(4):749–55. 10.1097/AOG.0000000000000467 25198275 doi:10.1097/AOG.0000000000000467 PubMed
  149. MikhaelM, BronsonC, ZhangL, CurranM, RodriguezH, BhaktaKY. Lack of evidence for time or dose relationship between antenatal magnesium sulfate and intestinal injury in extremely preterm neonates. Neonatology. 2019;115(4):371–8. 10.1159/000497412 30965340PMC6554036 doi:10.1159/000497412 PubMed
  150. MitaniM, MatsudaY, ShimadaE. Short- and long-term outcomes in babies born after antenatal magnesium treatment. J Obstet Gynaecol Res. 2011;37(11):1609–14. 10.1111/j.1447-0756.2011.01583.x 21733038 doi:10.1111/j.1447-0756.2011.01583.x PubMed
  151. MittendorfR, BesingerR, SantillanM, GianopoulosJ. When used in the circumstance of preterm labor, is there a paradoxical effect of varying exposures to magnesium sulfate (MgSO4) on the developing human brain? Am J Obstet Gynecol. 2005;193(6):S65.
  152. MittendorfR, PrydeP, GianopoulosJ, BesingerR, LeeK-S. Thalamostriate vasculopathy in the neonate is associated with antenatal exposures to tocolytic MgSO4. Am J Obstet Gynecol. 2009;201(6):S79.
  153. MoragI, OkrentAL, StraussT, Staretz-ChachamO, KuintJ, SimchenMJ, et al Early neonatal morbidities and associated modifiable and non-modifiable risk factors in a cohort of infants born at 34–35 weeks of gestation. J Matern Fetal Neonatal Med. 2015;28(8):876–82. 10.3109/14767058.2014.938043 24962498 doi:10.3109/14767058.2014.938043 PubMed
  154. MoragI, YakubovichD, SternO, Siman-TovM, Schushan-EisenI, StraussT, et al Short-term morbidities and neurodevelopmental outcomes in preterm infants exposed to magnesium sulphate treatment. J Paediatr Child Health. 2016;52(4):397–401. 10.1111/jpc.13103 27145502 doi:10.1111/jpc.13103 PubMed
  155. MoschosE, MageeK. Does magnesium sulfate exposure decrease the incidence of necrotizing enterocolitis? Am J Obstet Gynecol. 2001;185(6 Suppl):S148.
  156. MurataY, ItakuraA, MatsuzawaK, OkumuraA, WakaiK, MizutaniS. Possible antenatal and perinatal related factors in development of cystic periventricular leukomalacia. Brain Dev. 2005;27(1):17–21. 10.1016/j.braindev.2004.02.011 15626536 doi:10.1016/j.braindev.2004.02.011 PubMed
  157. NakamuraY, IbaraS, IkenoueT. Effect of maternally administered magnesium sulfate on the neonate. J Perinat Med. 1991;19(Suppl 2):136.
  158. NarasimhuluD, BrownA, EgbertNM, RojasM, HabermanS, BhutadaA, et al Maternal magnesium therapy, neonatal serum magnesium concentration and immediate neonatal outcomes. J Perinatol. 2017;37(12):1297–303. 10.1038/jp.2017.132 28981078 doi:10.1038/jp.2017.132 PubMed
  159. NassarAH, SakhelK, MaaroufH, NaassanGR, UstaIM. Adverse maternal and neonatal outcome of prolonged course of magnesium sulfate tocolysis. Acta Obstet Gynecol Scand. 2006;85(9):1099–103. 10.1080/00016340600756896 16929415 doi:10.1080/00016340600756896 PubMed
  160. NelsonKB, GretherJK. Can magnesium sulfate reduce the risk of cerebral palsy in very low birthweight infants? Pediatrics. 1995;95(2):263–9. 7838646 PubMed
  161. NunesRD, SchutzFD, TraebertJL. Association between the use of magnesium sulfate as neuroprotector in prematurity and the neonatal hemodynamic effects. J Matern Fetal Neonatal Med. 2018;31(14):1900–5. 10.1080/14767058.2017.1332033 28521581 doi:10.1080/14767058.2017.1332033 PubMed
  162. O ReillyE, RogersEL, HayesB. Effects of magnesium sulphate on respiratory function in the preterm infants who received magnesium sulphate prophylaxis at delivery. Ir J Med Sci. 2016;185:S277–8.
  163. OkusanyaBO, GarbaKK, IbrahimHM. The efficacy of 10gram intramuscular loading dose of MgSO(4) in severe preeclampsia/ eclampsia at a tertiary referral centre in Northwest Nigeria. Niger Postgrad Med J. 2012;19(3):143–8. 23064169 PubMed
  164. ÖzlüF, HacıoğluC, BüyükkurtS, YapıcıoğluH, SatarM. Changes on preterm morbidities with antenatal magnesium. Cukurova Med J. 2019;44(2):502–8. 10.17826/cumj.444238 doi:10.17826/cumj.444238
  165. PalatnikA, LiuLY, LeeA, YeeLM. Predictors of early-onset neonatal sepsis or death among newborns born at <32 weeks of gestation. J Perinatol. 2019;39(7):949–55. 10.1038/s41372-019-0395-9 31089257 doi:10.1038/s41372-019-0395-9 PubMed
  166. PanethN, JettonJ, Pinto-MartinJ, SusserM. Magnesium sulfate in labor and risk of neonatal brain lesions and cerebral palsy in low birth weight infants. The Neonatal Brain Hemorrhage Study Analysis Group. Pediatrics. 1997;99(5):E1 10.1542/peds.99.5.e1 9113958 doi:10.1542/peds.99.5.e1 PubMed
  167. PerlmanJ, FernandezC, GeeJ, LevenoK, RisserR. Magnesium sulphate (Mg) administered to mothers with pregnancy-induced hypertension (PIH) is associated with a reduction in periventricular-intraventricular hemorrhage (PV-IVH). Pediatr Res. 1995;37(4 Pt 2):231A.
  168. PetrovV, LupascuA, EtscoL, PavlencoA. Maternal and new born hemodynamics after antenatal administration of magnesium sulfate (MGSO4), as a neuroprotective drug in preterm birth. J Perinat Med. 2013;41(Suppl 1):RU350.
  169. PetrovaA, MehtaR. Magnesium sulfate tocolysis and intraventricular hemorrhage in very preterm infants. Indian J Pediatr. 2012;79(1):43–7. 10.1007/s12098-011-0440-y 21625843 doi:10.1007/s12098-011-0440-y PubMed
  170. QasimA, JainS, DasguptaS. Does antenatal magnesium sulfate increase the likelihood of a hemodynamically significant patent ductus arteriosus in neonates? J Investig Med. 2017;65(2):547–8.
  171. RantonenT, KaapaP, GronlundJ, EkbladU, HeleniusH, KeroP, et al Maternal magnesium sulfate treatment is associated with reduced brain-blood flow perfusion in preterm infants. Crit Care Med. 2001;29(7):1460–5. 10.1097/00003246-200107000-00026 11445708 doi:10.1097/00003246-200107000-00026 PubMed
  172. RaschDK, HuberPA, RichardsonCJ, L’HommedieuCS, NelsonTE, ReddiR. Neurobehavioral effects of neonatal hypermagnesemia. J Pediatr. 1982;100(2):272–6. 10.1016/s0022-3476(82)80654-9 7199083 doi:10.1016/s0022-3476(82)80654-9 PubMed
  173. RattrayBN, KrausDM, DrinkerLR, GoldbergRN, TanakaDT, CottenCM. Antenatal magnesium sulfate and spontaneous intestinal perforation in infants less than 25 weeks gestation. J Perinatol. 2014;34(11):819–22. 10.1038/jp.2014.106 24901451 doi:10.1038/jp.2014.106 PubMed
  174. RaufM, SevilE, EbruC, YavuzS, CemilC. Antenatal magnesium sulfate use for fetal neuroprotection: experience from a tertiary care hospital in Turkey. Biomed Res. 2017;28(4):1749–54.
  175. RheeE, BeiswengerT, OguejioforCE, JamesAH. The effects of magnesium sulfate on maternal and fetal platelet aggregation. J Matern Fetal Neonatal Med. 2012;25(5):478–83. 10.3109/14767058.2011.584087 21762000 doi:10.3109/14767058.2011.584087 PubMed
  176. RiazM, PoratR, BrodskyNL, HurtH. The effects of maternal magnesium sulfate treatment on newborns: a prospective controlled study. J Perinatol. 1998;18(6 Pt 1):449–54. 9848759 PubMed
  177. RizzoloA, ShahPS, BoucorianI, LemyreB, BertelleV, PelausaE, et al Cumulative effect of evidence-based practices on outcomes of preterm infants born at <29 weeks gestational age. Am J Obstet Gynecol. 2019 9 6 10.1016/j.ajog.2019.08.058 31499055 doi:10.1016/j.ajog.2019.08.058 PubMed
  178. SakaeC, SatoY, KanbayashiS, TagaA, EmotoI, MaruyamaS, et al Introduction of management protocol for early-onset severe pre-eclampsia. J Obstet Gynaecol Res. 2017;43(4):644–52. 10.1111/jog.13265 28150368 doi:10.1111/jog.13265 PubMed
  179. SahinH, AkayAF, BircanMK, GocmenA, BircanZ. The first micturition times of the newborns whose mothers were treated with magnesium sulfate. Int Urol Nephrol. 2001;32(4):651–3. 10.1023/a:1014405824678 11989558 doi:10.1023/a:1014405824678 PubMed
  180. SalafiaCM, MiniorVK, RosenkrantzTS, PezzulloJC, PopekEJ, CusickW, et al Maternal, placental, and neonatal associations with early germinal matrix/intraventricular hemorrhage in infants born before 32 weeks’ gestation. Am J Perinatol. 1995;12(6):429–36. 10.1055/s-2007-994514 8579656 doi:10.1055/s-2007-994514 PubMed
  181. SarkarS, BhagatI, DechertR, SchumacherRE, DonnSM. Severe intraventricular hemorrhage in preterm infants: comparison of risk factors and short-term neonatal morbidities between grade 3 and grade 4 intraventricular hemorrhage. Am J Perinatol. 2009;26(6):419–24. 10.1055/s-0029-1214237 19267317 doi:10.1055/s-0029-1214237 PubMed
  182. SchanlerRJ, SmithLG, BurnsPA. Effects of long-term maternal intravenous magnesium sulfate therapy on neonatal calcium metabolism and bone mineral content. Gynecol Obstet Invest. 1997;43(4):236–41. 10.1159/000291864 9194621 doi:10.1159/000291864 PubMed
  183. ScudieroR, KhoshnoodB, PrydePG, LeeKS, WallS, MittendorfR. Perinatal death and tocolytic magnesium sulfate. Obstet Gynecol. 2000;96(2):178–82. 10.1016/s0029-7844(00)00893-0 10908759 doi:10.1016/s0029-7844(00)00893-0 PubMed
  184. ShalabiM, MohamedA, LemyreB, AzizK, FaucherD, ShahPS, et al Antenatal exposure to magnesium sulfate and spontaneous intestinal perforation and necrotizing enterocolitis in extremely preterm neonates. Am J Perinatol. 2017;34(12):1227–33. 10.1055/s-0037-1603344 28494498 doi:10.1055/s-0037-1603344 PubMed
  185. ShamsuddinL, NaharK, NasrinB, NaharS, TamannaS, KabirRM, et al Use of parenteral magnesium sulphate in eclampsia and severe pre-eclampsia cases in a rural set up of Bangladesh. Bangladesh Med Res Counc Bull. 2005;31(2):75–82. 16967813 PubMed
  186. ShokryM, ElsedfyGO, BassiounyMM, AnminM, AbozidH. Effects of antenatal magnesium sulfate therapy on cerebral and systemic hemodynamics in preterm newborns. Acta Obstet Gynecol Scand. 2010;89(6):801–6. 10.3109/00016341003739542 20504082 doi:10.3109/00016341003739542 PubMed
  187. StetsonBT, BuhimschiCS, KellertBA, HayK, BuhimschiIA, MaitreNL. Comparison of cerebral palsy severity between 2 eras of antenatal magnesium use. JAMA Pediatr. 2019;173(2):188–90. 10.1001/jamapediatrics.2018.3827 30508016PMC6439606 doi:10.1001/jamapediatrics.2018.3827 PubMed
  188. StockleyEL, TingJY, KingdomJC, McDonaldSD, BarrettJF, SynnesAR, et al Intrapartum magnesium sulfate is associated with neuroprotection in growth-restricted fetuses. Am J Obstet Gynecol. 2018;219(6):606e1–8.3024065110.1016/j.ajog.2018.09.010 doi:10.1016/j.ajog.2018.09.010 PubMed
  189. SuhB, KoK, BangJ, OhY, LeeY, LeeJ, et al Neonatal outcomes of premature infants who were delivered from mother with hypertensive disorders of pregnancy and effects of antihypertensive drugs and MgSO4. Korean J Perinatol. 2015;26(3):190–9.
  190. TengRJ, WuTJ, SharmaR, GarrisonRD, HudakML. Early neonatal hypotension in premature infants born to preeclamptic mothers. J Perinatol. 2006;26(8):471–5. 10.1038/sj.jp.7211558 16775620 doi:10.1038/sj.jp.7211558 PubMed
  191. VermaRP, ChandraS, NiwasR, KomaroffE. Risk factors and clinical outcomes of pulmonary interstitial emphysema in extremely low birth weight infants. J Perinatol. 2006;26(3):197–200. 10.1038/sj.jp.7211456 16493434 doi:10.1038/sj.jp.7211456 PubMed
  192. WeintraubZ, SolovechickM, ReichmanB, RotschildA, WaismanD, DavkinO, et al Effect of maternal tocolysis on the incidence of severe periventricular/intraventricular haemorrhage in very low birthweight infants. Arch Dis Child Fetal Neonatal Ed. 2001;85(1):F13–7. 10.1136/fn.85.1.F13 11420315PMC1721274 doi:10.1136/fn.85.1.F13 PubMed
  193. WeiszD, ShivanandaS, AsztalosE, YeeW, SynnesA, LeeS, et al Intrapartum magnesium sulfate and need for intensive delivery room resuscitation. Arch Dis Child Fetal Neonatal Ed. 2015;100(1):F59–65. 10.1136/archdischild-2013-305884 25232002 doi:10.1136/archdischild-2013-305884 PubMed
  194. WhitselA, InselA, DesilvaH, BernsteinB. Association of maternal antepartum management with mortality and morbidity of the extremely low birthweight (ELBW) neonate. Am J Obstet Gynecol. 2004;191(6 Suppl):S75.
  195. WhittenA, OgunyemiD, BetcherK, NowakowskiA, QuS. What factors predict prolonged neonatal length of stay in term babies? Int J Gynaecol Obstet. 2015;131:E462–3.
  196. WiswellTE, CaddellJL, GrazianiLJ, KornhauserMS, SpitzerAR. Maternally-administered magnesium sulfate (MgSO4) decreases the incidence of severe necrotizing enterocolitis (NEC) in preterm infants: a prospective study. Pediatr Res. 1996;39(4):1501.
  197. WutthigateP, YangtharaB, SiripattanapipongP, KitsommartR. Correlation between maternal cumulative dose of intrapartum magnesium sulfate and cord blood magnesium level. Southeast Asian J Trop Med Public Health. 2017;48(Suppl 2):256–63.
  198. YokoyamaK, TakahashiN, YadaY, KoikeY, KawamataR, UeharaR, et al Prolonged maternal magnesium administration and bone metabolism in neonates. Early Hum Dev. 2010;86(3):187–91. 10.1016/j.earlhumdev.2010.02.007 20226604 doi:10.1016/j.earlhumdev.2010.02.007 PubMed
  199. YoungBK, WeinsteinHM. Effects of magnesium sulfate on toxemic patients in labor. Obstet Gynecol. 1977;49(6):681–5. 865731 PubMed
  200. AhmadS, MillerM, SlaughterS. Is there any evidence for fetal harm with prolonged used of magnesium sulfate in pregnant women? Pharmacoepidemiol Drug Saf. 2013;22(1):141.
  201. AmodioJ, BerdonW, AbramsonS, StolarC. Microcolon of prematurity: a form of functional obstruction. AJR Am J Roentgenol. 1986;146(2):239–44. 10.2214/ajr.146.2.239 3484569 doi:10.2214/ajr.146.2.239 PubMed
  202. CruzM, DorenA, FernandezB, Antonio SalinasJ, UrzuaS, Lui TapiaJ. Intoxicación neonatal por sulfato de magnesio: caso clínico. Rev Chil Pediatr. 2009;80(3):261–6.
  203. CummingW, ThomasV. Hypermagnesemia: a cause of abnormal metaphyses in the neonate. AJR Am J Roentgenol. 1989;152(5):1071–2. 10.2214/ajr.152.5.1071 2705341 doi:10.2214/ajr.152.5.1071 PubMed
  204. HerschelM, MittendorfR. Tocolytic magnesium sulfate toxicity and unexpected neonatal death. J Perinatol. 2001;21(4):261–2. 10.1038/sj.jp.7200498 11533846 doi:10.1038/sj.jp.7200498 PubMed
  205. BradyJ. Magnesium intoxication in a premature infant. Pediatrics. 1967;40(1):100–3. 6028888 PubMed
  206. JashiR, GorgadzeN. Maternal medication part of infant mortality. J Matern Fetal Neonatal Med. 2014;27:320–1.23875873
  207. KaplanW, HaymondMW, McKayS, KaravitiLP. Osteopenic effects of MgSO4 in multiple pregnancies. J Pediatr Endocrinol Metab. 2006;19(10):1225–30. 10.1515/jpem.2006.19.10.1225 17172083 doi:10.1515/jpem.2006.19.10.1225 PubMed
  208. KoganJM, WedigKE, WhitsettJA, SchorryEK. Prolonged prenatal exposure to magnesium sulfate associated with bone abnormalities mimicking genetic bone disease. Am J Hum Genet. 2003;73(5 Suppl):590.
  209. KrasnaIH, RosenfeldD, SalernoP. Is it necrotizing enterocolitis, microcolon of prematurity, or delayed meconium plug? A dilemma in the tiny premature infant. J Pediatr Surg. 1996;31(6):855–8. 10.1016/s0022-3468(96)90153-0 8783123 doi:10.1016/s0022-3468(96)90153-0 PubMed
  210. KurtogluS, CaksenH, PoyrazogluMH. Neonatal poisonings in middle Anatolia of Turkey: an analysis of 72 cases. J Toxicol Sci. 2000;25(2):115–9. 10.2131/jts.25.115 10845189 doi:10.2131/jts.25.115 PubMed
  211. L’HommedieuCS, HuberP, RaschDK. Potentiation of magnesium-induced neuromuscular weakness by gentamicin. Crit Care Med. 1983;11(1):55–6. 10.1097/00003246-198301000-00015 6848309 doi:10.1097/00003246-198301000-00015 PubMed
  212. LammC, NortonK, MurphyR, WilkinsI, RabinowitzJ. Congenital rickets associated with magnesium sulfate infusion for tocolysis. J Pediatr. 1988;113(6):1078–82. 10.1016/s0022-3476(88)80586-9 3193315 doi:10.1016/s0022-3476(88)80586-9 PubMed
  213. LipsitzP, EnglishI. Hypermagnesemia in the newborn infant. Pediatrics. 1967;40(5):856–62. 6075658 PubMed
  214. MalaebS, RassiA, HaddadM, SeoudM, YunisK. Bone mineralization in newborns whose mothers received magnesium sulphate for tocolysis of preterm labour. Pediatr Radiol. 2004;34(384–6).10.1007/s00247-004-1148-114985884 doi:10.1007/s00247-004-1148-1 PubMed
  215. RaschD, RichardsonC. Effect of gentamicin on neuromuscular function (NMF) of a hypermagnesemic neonate. Pediatr Res. 1981;15(4):499.
  216. SokalM, KoenigsbergerM, RoseJ, BerdonW, SantulliT. Neonatal hypermagnesemia and the meconium-plug syndrome. N Engl J Med. 1972;286(1):823–5.501179010.1056/NEJM197204132861507 doi:10.1056/NEJM197204132861507 PubMed
  217. TanakaK, MoriH, SakamotoR, MatsumotoS, MitsubuchiH, NakamuraK, et al Early-onset neonatal hyperkalemia associated with maternal hypermagnesemia: a case report. BMC Pediatr. 2018;15(1):55.10.1186/s12887-018-1048-4PMC580984229433462 doi:10.1186/s12887-018-1048-4 PubMed
  218. TengR, LiuH, Tsou YauK. Neonatal hypermagnesemia: report of one case. Acta Paediatr Sin. 1989;30(5):333–6. 2637615 PubMed
  219. SmithJM, LoweRF, FullertonJ, CurrieSM, HarrisL, Felker-KantorE. An integrative review of the side effects related to the use of magnesium sulfate for pre-eclampsia and eclampsia management. BMC Pregnancy Childbirth. 2013;13:34 10.1186/1471-2393-13-34 23383864PMC3570392 doi:10.1186/1471-2393-13-34 PubMed
  220. DuffyJ, HirschM, PealingL, ShowellM, KhanKS, ZieblandS, et al Inadequate safety reporting in pre-eclampsia trials: a systematic evaluation. Br J Obstet Gynaecol. 2018;125(7):795–803.10.1111/1471-0528.1496929030992 doi:10.1111/1471-0528.14969 PubMed
  221. McNamaraHC, CrowtherCA, BrownJ. Different treatment regimens of magnesium sulphate for tocolysis in women in preterm labour. Cochrane Database Syst Rev. 2015;(12):CD011200 10.1002/14651858.CD011200.pub2 26662716PMC8697562 doi:10.1002/14651858.CD011200.pub2 PubMed
  222. GargBD. Antenatal magnesium sulfate is beneficial or harmful in very preterm and extremely preterm neonates: a new insight. J Matern Fetal Neonatal Med. 2019;32(12):2084–90. 10.1080/14767058.2018.1424823 29301419 doi:10.1080/14767058.2018.1424823 PubMed
  223. GolderS, LokeYK, WrightK, NormanG. Reporting of adverse events in published and unpublished studies of health care interventions: a systematic review. PLoS Med. 2016;13(9):e1002127 10.1371/journal.pmed.1002127 27649528PMC5029817 doi:10.1371/journal.pmed.1002127 PubMed
  224. SheaBJ, ReevesBC, WellsG, ThukuM, HamelC, MoranJ, et al AMSTAR 2: a critical appraisal tool for systematic reviews that include randomised or non-randomised studies of healthcare interventions, or both. BMJ. 2017;358:j4008 10.1136/bmj.j4008 28935701PMC5833365 doi:10.1136/bmj.j4008 PubMed

Attribution. Emily Shepherd, Rehana A. Salam, Deepak Manhas, Anne Synnes, Philippa Middleton, Maria Makrides et al.. Antenatal magnesium sulphate and adverse neonatal outcomes: A systematic review and meta-analysis. PLoS Medicine (2019);16(12). doi:10.1371/journal.pmed.1002988 © 2019 Shepherd et al Licensed under CC BY 4.0. Reproduced from the open-access article via Europe PMC (PubMed 31809499). Text, tables and references reproduced from the open-access article; figures and images are not reproduced and no wording was changed.

About this article

Journal
PLoS Medicine
Year
2019
Licence
CC BY 4.0
Source
Europe PMC
PubMed
31809499
Field
Kidney, Urology and Women's Health

EvidenceLib is a research-education resource, not medical advice. It does not diagnose, prescribe or recommend starting, stopping or changing any treatment. Talk to a qualified clinician about your own situation. Methods, sources and licences · Rights and removal requests · Legal · Support