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Background: Exposure to air pollution in prenatal period is associated with prelabor rupture of membranes (PROM). However, the sensitive exposure time windows and the possible biological mechanisms underlying this association remain unclear. Objective: We aimed to identify the sensitive time windows of exposure to air pollution for PROM risk. Further, we examined whether maternal hemoglobin levels mediate the association between exposure to air pollution and PROM, as well as investigated the potential effect of iron supplementation on this association. Method: From 2015 to 2021, 6,824 mother-newborn pairs were enrolled in the study from three hospitals in Hefei, China. We obtained air pollutant data [particulate matter (PM) with aerodynamic diameter [less than or equal to]2.5 [micro]m (P[M.sub.2.5]), PM with aerodynamic diameter [less than or equal to] 10 [micro]m (P[M.sub.10]), sulfur dioxide (S[O.sub.2]), and carbon monoxide (CO)] from the Hefei City Ecology and Environment Bureau. Information on maternal hemoglobin levels, gestational anemia, iron supplementation, and PROM was obtained from medical records. Logistic regression models with distributed lags were used to identify the sensitive time window for the effect of prenatal exposure to air pollutant on PROM. Mediation analysis estimated the mediated effect of maternal hemoglobin in the third trimester, linking prenatal air pollution with PROM. Stratified analysis was used to investigate the potential effect of iron supplementation on PROM risk. Results: We found significant association between prenatal exposure to air pollution and increased PROM risk after adjusting for confounders, and the critical exposure windows of P[M.sub.2.5], P[M.sub.10], S[O.sub.2] and CO were the 21th to 24th weeks of pregnancy. Every 10-[micro]g/[m.sup.3] increase in P[M.sub.2.5] and P[M.sub.10], 5-[micro]g/[m.sup.3] increase in S[O.sub.2], and 0.1-mg/[m.sup.3] increase in CO was associated with low maternal hemoglobin levels [-0.94 g/L (95% confidence interval (CI): -1.15, -0.73), -1.31 g/L (95% CI: -1.55, -1.07), -2.96 g/L (95% CI: -3.32, -2.61), and -1.11 g/L (95% CI: - 1.31, -0.92), respectively] in the third trimester. The proportion of the association between air pollution and PROM risk mediated by hemoglobin levels was 20.61% [average mediation effect (95% CI): 0.02 (0.01, 0.05); average direct effect (95%): 0.08 (0.02, 0.14)]. The PROM risk associated with exposure to low-medium air pollution could be attenuated by maternal iron supplementation in women with gestational anemia. Conclusions: Prenatal exposure to air pollution, especially in the 21st to 24th weeks of pregnancy, is associated with PROM risk, which is partly mediated by maternal hemoglobin levels. Iron supplementation in anemia pregnancies may have protective effects against PROM risk associated with exposure to low-medium air pollution. https://doi.org/10.1289/EHP11134, Introduction Air pollution is associated with health problems, including pregnancy-associated complications and increased adverse pregnancy outcomes. (1-3) Prelabor rupture of membranes (PROM) affects 3% to 21% of all pregnant women [...]

Context: The association of maternal gestational diabetes mellitus (GDM) with neurodevelopmental outcomes remains controversial and evidence that maternal increasing levels of glucose during pregnancy associated with the risk for impaired neurodevelopment were limited.Objective: To identify the continuous association of increasing maternal glucose levels with neurodevelopmental disorders in offspring and explore the potential contribution of cord metabolites to this association.Methods: The prospective birth cohort study included 1036 mother-child pairs. Primary predictors were maternal exposure GDM and maternal glucose values at a 75-g oral-glucose-tolerance test at 24 to 28 weeks during pregnancy. Primary neurodevelopmental outcomes at 12 months in offspring were assessed by the Ages and Stages Questionnaires, Third Edition (ASQ-3).Results: Maternal GDM was associated with failing the communication domain in offspring in the adjusted models [relative risk (RR) with 95% CI: 1.97 (1.11, 3.52)]. Increasing levels of fasting plasma glucose (FPG), 1-h plasma glucose (1-h PG) and 2-h plasma glucose (2-h PG) with 1 SD change were at higher risks in failing the personal social domain of ASQ-3 [RRs with 95% CI for FPG: 1.49 (1.09, 2.04); for 1-h PG: 1.70 (1.27, 2.29); for 2-h PG: 1.36 (1.01, 1.84)]. The linear association was also demonstrated. Compared with girls, boys exposed to higher maternal glucose levels were inclined to the failure of the personal social domain. Mediation analysis showed the contribution of maternal GDM to failure of communication domain mediated by C-peptide.Conclusions: Maternal glucose levels below those diagnostic of diabetes are continuously associated with impaired neurodevelopment in offspring at 12 months. [ABSTRACT FROM AUTHOR]