Birth Weight

ImportanceMetabolic dysfunction-associated steatotic liver disease (MASLD) has become the most common chronic liver disease worldwide and is increasingly being diagnosed at younger ages, affecting more than one-third of young people with obesity.ObjectiveTo evaluate associations between perinatal conditions and risk of MASLD and associated progressive liver disease.Design, setting, and participantsThis nationwide, population-based case-control study included all biopsy-confirmed cases of MASLD in Sweden. Individuals aged 25 years or younger (hereafter, young individuals) with biopsy-proven MASLD between January 1, 1992, and December 31, 2016, were matched to up to 5 general population control individuals. Granular data on maternal and perinatal characteristics were retrieved from the Swedish Medical Birth Register. Data were analyzed from June 2023 to June 2024.ExposuresBirth weight (low [90th percentile]), compared between patients and matched controls.Main outcomes and measuresThe main outcome was odds of biopsy-proven MASLD and MASLD-associated progressive liver disease (ie, liver fibrosis or cirrhosis) according to birth weight, GA, and birth weight for GA, adjusted for matching factors.ResultsIn total, 165 young individuals with biopsy-proven MASLD (median age at diagnosis: 12.0 years [IQR, 4.4-16.9 years]; 100 [60.6%] male) were matched with 717 controls. There was an association between low birth weight and future development of MASLD (adjusted odds ratio [AOR], 4.05; 95% CI, 1.85-8.88) but no association between high birth weight and odds of MASLD (AOR, 0.64; 95% CI, 0.38-1.08) compared with the reference birth weight. An association was seen for SGA (AOR, 3.36; 95% CI, 2.00-5.64) compared with appropriate size for GA (reference category) but not for LGA (AOR, 0.57; 95% CI, 0.27-1.20). Progressive liver disease was more common in individuals born with low birth weight (AOR, 6.03; 95% CI, 1.66-21.87) or SGA (AOR, 4.90; 95% CI, 2.15-11.14).Conclusions and relevanceIn this nationwide study of young individuals with biopsy-proven MASLD, low birth weight and SGA were associated with development of MASLD and progressive liver disease, suggesting a need for structured screening measures to diagnose these conditions early in high-risk individuals.

ImportancePolycystic ovary syndrome (PCOS) is a common endocrine disorder, characterized by subfertility, increased risk of metabolic diseases, and pregnancy complications. Previous studies diverge regarding the association between maternal PCOS and newborn anthropometrics.ObjectiveTo explore the association between maternal PCOS and newborn anthropometrics and the modifying effects of maternal body mass index, PCOS phenotype, and gestational diabetes.Design, setting, and participantsThis cohort study followed up women from the first half of pregnancy to birth and combined data from 3 clinical trials of pregnant women with PCOS and a reference population consisting of participants in the Norwegian Mother, Father, and Child Cohort (MoBa) Study, with data from the Medical Birth Registry of Norway. The recruitment period for the clinical trials was between October 1, 2000, and August 31, 2017, and for MoBa, between July 1, 1999, and December 31, 2008. Participants included women with singleton pregnancies and live-born children. Data were analyzed from January 1 to June 15, 2023.ExposureMaternal PCOS status.Main outcomes and measuresNewborn birth weight, birth length, and head circumference as continuous variables and z scores, and ponderal index (calculated as the birth weight in grams × 100 divided by the birth length in centimeters cubed), placenta weight, and ratio of birth weight to placenta weight (BWPW).ResultsThe cohort included 390 pregnant women with PCOS (mean [SD] age, 29.6 [4.2] years) and 68 708 women in the reference group (mean [SD] age, 30.4 [4.5] years). Offspring in the PCOS group had lower birth weight, birth length, and head circumference than in the reference group offspring. The estimated mean differences in z scores were -0.26 (95% CI, -0.38 to -0.14) for birth weight, -0.19 (95% CI, -0.33 to -0.05) for birth length, and -0.13 (95% CI, -0.26 to -0.01) for head circumference. The PCOS group also had a lower ponderal index (-0.04 [95% CI, -0.07 to -0.004] g × 100/cm3) and placenta weight (-24 [95% CI, -43 to -5)] g), and higher BWPW ratio (0.4 [95% CI, 0.3 to 0.5]). The association between growth restriction and PCOS was more apparent when additionally adjusting for body mass index. Neither PCOS phenotype nor gestational diabetes diagnosis was associated with neonatal anthropometry in women with PCOS.Conclusions and relevanceIn this cohort of mother-infant pairs, maternal PCOS status was associated with lower birth weight, shorter birth length, and smaller head circumference in the offspring. This growth restriction was more pronounced when adjusting for BMI, providing insight into the association between PCOS and body mass index. The study contributed to the understanding of how PCOS affects the offspring.

BackgroundThe neonatal outcomes across different percentiles of birth weight for gestational age are still unclear.MethodsThis retrospective cohort study was conducted within 57 tertiary hospitals participating in the Chinese Neonatal Network (CHNN) from 25 provinces throughout China. Infants with gestational age (GA) 24+0-31+6 weeks who were admitted within 7 days after birth were included. The composite outcome was defined as mortality or any one of neonatal major morbidities, including necrotizing enterocolitis (NEC), bronchopulmonary dysplasia (BPD), severe intraventricular hemorrhage (IVH), cystic periventricular leukomalacia (cPVL), severe retinopathy of prematurity (ROP), and sepsis. Multivariable logistic regressions using generalized estimating equation approach were conducted.ResultsA total of 8380 infants were included with a mean GA of 30 (28-31) weeks. Of these, 1373 (16.5%) were born at less than 28 weeks, while 6997 (83.5%) had a GA between 28 and 32 weeks. Our analysis indicated that the risk of composite outcomes was negatively associated with birth weight for gestational age, and compared to the reference group, the multiple-adjusted ORs (95%CI) of composite outcomes were 4.89 (3.51-6.81) and 2.16 (1.77-2.63) for infants with birth weight for gestational less than 10th percentile and 10th -30th percentile, respectively. The ORs (95%CI) of mortality, NEC, BPD, severe ROP, and sepsis in infants with birth weight for gestational age at 10th-30th percentile were 1.94 (1.56-2.41), 1.08 (0.79-1.47), 2.48 (2.03-3.04), 2.35 (1.63-3.39), and 1.39 (1.10-1.77), respectively.ConclusionOur study suggested that the risk of adverse neonatal outcomes increased significantly when the birth weight for gestational age was below the 30th percentile. Regular monitoring and early intervention are crucial for these high-risk infants.

BackgroundEarly gestational weight gain (E-GWG) plays a crucial role in fetal development. Its timing and sex-specific impacts have not been thoroughly investigated, especially in Asian populations.MethodsIn this retrospective cohort study, 66,291 mother-infant pairs from the Tianjin Women and Children's Health Care System were analyzed. Linear and logistic regression models were applied to examine the association between E-GWG and birth weight outcomes across BMI groups. We also analyzed the effects of E-GWG on the birth weight of infants born to pregnant women carrying male and female fetuses, respectively.ResultsE-GWG had a stronger impact on birth weight z-scores than late GWG (β 0.038 vs. 0.016, P ConclusionsInsufficient E-GWG of women with underweight highlights the risk of female SGA. Pregnant women with excessive E-GWG should be aware of the risk of LGA, especially those carrying female fetuses.ImpactEarly GWG showed stronger impacts on birth weight outcomes (LGA/SGA) than late GWG, with BMI/sex effects. Female fetuses showed higher LGA odds with excessive E-GWG in moms with overweight/obesity; insufficient E-GWG in moms with underweight strongly correlated with female-specific SGA vulnerability. Findings warrant BMI/sex-tailored GWG guidelines to optimize Asian perinatal health and reduce long-term metabolic risks.