Pregnancy Outcome

BackgroundMaternal anaemia is a public health issue globally, associated with adverse maternal and neonatal outcomes. However, less is known about the effects of high haemoglobin (Hb) and haematocrit (Hct) on the risk of stillbirth.ObjectivesWe assessed the dose-response effects of dynamic changes in maternal Hb and Hct across all trimesters on stillbirth risk.MethodsThis study was based on the prospective, longitudinal, population-based China birth cohort study (CBCS) between 2018 and 2022, including 142,715 women with live births or stillbirths delivered at ≥ 20 weeks' gestation. The modified Poisson regression models were used to assess the association between Hb/Hct, haemodilution status across three trimesters and stillbirth.ResultsOver a fifth (23.6%) of pregnant women had anaemia at least once during pregnancy. Maternal anaemia increased the risk of stillbirth. The adjusted risk ratio (aRR) for Hb at 70-99 g/L (moderate anaemia) was 2.45, 95% confidence interval (CI) 1.26, 4.76 and aRR for Hct ConclusionsConsidering the U-shaped association between Hb/Hct levels and stillbirth, clinical vigilance is necessary at both low- and high-extremes of Hb/Hct and physiological haemodilution metrics in mid-to-late pregnancy for improved pregnancy outcomes.

ImportanceGestational environmental chemical exposures are widespread. Some chemicals are known to adversely affect birth outcomes, but many remain understudied.ObjectiveTo evaluate associations of gestational exposure to a priori identified chemicals in 10 classes with birth outcomes in a large, diverse US cohort.Design, setting, and participantsIn the prospective Environmental influences on Child Health Outcomes Cohort study, 5318 mother-child pairs were enrolled from January 1, 2000, to December 31, 2021, with data on gestational urinary chemical concentrations, gestational age at birth, and birth weight. Statistical analysis was performed from January 2024 to February 2026.ExposuresIn single, midgestation (median, 25 weeks [IQR, 21-30 weeks]) urine samples, concentrations of 113 analytes (chemicals or their metabolites) from 10 chemical classes were simultaneously measured: fungicides and herbicides (n = 11), insecticides (n = 20), halogenated phenols (n = 5), organophosphate esters (n = 10), benzophenones (n = 6), bisphenols (n = 14), parabens (n = 6), antimicrobials (n = 2), phthalates or alternative plasticizers (n = 32), and polycyclic aromatic hydrocarbons (PAHs) (n = 7).Main outcomes and measuresLinear mixed-effects regression models with a random effect for site were used to estimate covariate-adjusted differences in gestational age at birth (days) and birth weight-for-gestational age (BW-GA) z scores per IQR increase in urinary analyte concentrations. In secondary analyses, odds ratios (ORs) for preterm birth and small for gestational age (SGA) were estimated.ResultsIn the sample of 5318 mother-child pairs, most infants (2667 female [50%]; median gestational age at birth, 39.0 weeks [IQR, 38.0-40.0 weeks]) were born to college-educated (67% [3218 of 4785]), parous (56% [2815 of 5007]) mothers (median age at delivery, 30.7 years [IQR, 26.1-34.3 years]). A total of 43 of 113 analytes (38%) were detected in 50% or more of samples. Multiple phthalates or alternative plasticizers were associated with younger gestational age at birth or lower BW-GA z scores; for example, summed diisononyl phthalate metabolites were associated with a 0.6-day (95% CI, -1.0 to -0.1 days) younger gestational age (preterm birth OR, 1.16 [95% CI, 1.01-1.34]), and summed phthalate or alternative plasticizers were associated with a 0.06 (95% CI, -0.11 to -0.02) lower BW-GA z score (SGA OR, 1.09 [95% CI, 0.93-1.27]). Two halogenated phenols, benzophenone 8, bisphenol F, and several PAHs were associated with lower BW-GA z scores; for example, 1- and 9-hydroxphenanthrene were associated with a 0.04 (95% CI, -0.08 to -0.01) lower BW-GA z score (SGA OR, 1.13 [95% CI, 1.01-1.27]).Conclusions and relevanceThis large cohort study of diverse US pregnancies found widespread exposure to 10 classes of environmental chemicals, many of which were associated with differences in gestational age at birth or lower BW-GA z scores. These findings indicate that reducing gestational exposure to chemicals, particularly phthalates or alternative plasticizers and PAHs, could promote healthy deliveries and better child outcomes.

BackgroundEarly pregnancy loss (EPL), a spontaneous death of the embryo or foetus occurring within the first trimester, is a major challenge for human reproduction with profound adverse consequences for women's health. Currently, reliable blood-based biomarkers for EPL remain limited. Therefore, there is an urgent need to discover novel biomarkers for EPL using a multi-omics-based approach to facilitate early detection and timely management.MethodsIn the discovery cohort, 40 patients with EPL and 40 healthy pregnancies (HP) at 7-13 weeks of gestation were enrolled. Serum proteins and metabolites were assayed by Olink® technology and ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS), respectively. Biomarkers were defined by false discovery rate (FDR) 1.2. Random forest (RF) and logistic regression (LR) models incorporating selected biomarkers were employed to develop diagnostic models for EPL. In the external validation cohort, we prospectively enrolled 142 pregnancies at 7-10 gestational weeks, including 47 subjects who subsequently developed EPL and 95 pregnancies with full-term birth. Serum levels of selected biomarkers were quantified by ELISA.FindingsThe combined proteomics and metabolomics screening identified 26 proteins and 21 metabolites significantly changed in the EPL group and tightly associated with EPL-related clinical phenotypes, with functional enrichment in immunoregulation and lipid oxidation processes. Moreover, integrating serum levels of angiopoietin-like 4 (ANGPTL4), programmed death-ligand 1 (PD-L1), neutrophil%, and lymphocyte% achieved an AUC of 0.944 (95% CI: 0.835-1.000) in the random forest model and 0.954 (95% CI: 0.875-1.000) in the logistic regression model to discriminate EPL from HP. Importantly, this four-biomarker model achieved an AUC of 0.857 (95% CI: 0.747-0.968) in the random survival forest model and a C-index of 0.804 (95% CI: 0.685-0.973) in the validation cohort for EPL prediction.InterpretationOur integrative omics study reveals a panel of potential circulating biomarkers for EPL, which further offer mechanistic insights into EPL pathogenesis, including impaired maternal immune tolerance and dysregulated lipid metabolism pathways. Moreover, the newly identified biomarkers exhibit promising diagnostic and predictive performance for EPL, underscoring its clinical translational value for human reproduction and maternal-foetal health.FundingThis study was supported by Research Grants Council (RGC) Germany/Hong Kong Joint Research Scheme (G-CUHK415/25), 1+1+1 CUHK-CUHK(SZ)-GDST Joint Collaboration Fund (2025A0505000077), CUHK HOPE BWCH Collaborative Medical Research Fund (CF2025002), Shenzhen Medical Research Fund (C2501040), and Shenzhen Science and Technology Program (RCYX20210609104608036).