Gender-specific effects of prenatal mixed exposure to serum phthalates on neurodevelopment of children aged 2-3 years:the Guangxi Birth Cohort Study.

Phthalates have been shown to have adverse effects on neurodevelopment, which may be gender-specific. However, the association between prenatal mixed exposure to phthalates and children's neurodevelopment remains inconsistent. We measured 15 prenatal serum phthalate levels and evaluated children's neurodevelopmental indicators using Gesell Developmental Schedule (GDS) (n = 750). Generalized linear regression was fitted to examine the association. Among boys, mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) had adverse effects on gross motor [odds ratio (OR): 7.38, 95% confidence interval (CI):1.42, 38.46]. For gross motor in boys, joint effect was discovered between mono-2-ethylhexyl phthalate (MEHP) and MEHHP. Moreover, synergistic effects were found for MEHP with vanadium and cadmium, and antagonistic effects for MEHP with magnesium, calcium, titanium, iron, copper, selenium, rubidium, and strontium. We did not find statistically significant relationships in girls. In the 1st trimester, adverse effects were identified between mono-2-ethyl-5-oxoyhexyl phthalate (MEOHP) and adaptation (P = 0.024), and monomethyl phthalate (MMP) with social area (P = 0.017). In the 2nd trimester, MEHHP had adverse effects on social area (P = 0.035). In summary, we found boys may be more vulnerable to the neurotoxicity than girls in gross motor, and we also discovered the detrimental effects of phthalates on children's neurodevelopment in the 1st and 2nd trimesters. Therefore, the supplementation of appropriate elements in the 1st and 2nd trimesters may help reduce the adverse effects of phthalates on children's neurodevelopment, especially among boys.

Low serum folate status in the second trimester increase the risk of low birthweight in Chinese women.

AIM: This study aimed to explore the influence of maternal folate and vitamin B12 (B12) status during pregnancy on the incidence of low birthweight (LBW) infants. METHODS: A total of 6203 eligible women registered in seven hospitals in southern China, and 230 cases with singleton live births and 382 controls were matched for further analyses. The concentrations of serum folate and B12 were detected with chemiluminescence microparticle immunoassay on ARCHITECT i2000-1. Conditional logistic regression was used to evaluate the effects of folate and B12 levels on LBW. RESULTS: Maternal serum folate levels increased basically with increasing the period of folic acid supplementation (P trend <0.001). Moreover, maternal serum folate and B12 levels gradually decreased with the increase of gestational age (P < 0.001). Conditional logistic regressions analysis results showed increased odds ratios (OR) for LBW from the fourth to first folate quartiles (P trend <0.01) in the second trimester. Compared with the women in the highest quartile, those in the lowest quartile of serum folate in the second trimester were found with higher risk of LBW (adjusted OR = 1.67, 95% confidence interval [CI]: 1.02-2.73). However, no significant association was observed between serum folate and LBW in the first trimester or third trimester. In addition, serum B12 exhibited no significant association with LBW. CONCLUSIONS: Low serum folate levels in the second trimester significantly increases the risk of LBW amongst Chinese women with singleton pregnancies.