Relationship of parental phthalate exposure with fetal growth and placental development at birth

Background: Prenatal exposure to phthalates is reported to influence fetal growth and may lead to lasting adverse effects on infants and their future development; yet, the results remain inconclusive. Objective: This study utilized a birth cohort of 73 pregnant women-newborn pairs, including biological fathers (73 triads), to investigate the relationship between parental phthalate exposure during pregnancy and birth outcomes in newborns. Methods: Demographic, behavioral, and clinical information, along with urine samples from both parents, were collected prior to delivery. Sixteen phthalate metabolites were quantified in urine samples. Results: Significant correlations were observed between six phthalate metabolites (MEP, MiBP, MnBP, MBzP, MEHP, and 5cx-MEPP) in maternal urine and paternal levels. Maternal MBzP was positively associated with boys’ birth weight, whereas maternal 2cx-MMHP was negatively associated with girls’ birth weight. The ponderal index of boys was negatively related to maternal MBzP and MMP, but positively associated with ∑MEHP-3 and ∑MEHP-5 after adjusting for confounding variables. Among paternal phthalates, MBzP showed a negative association with boys’ ponderal index, whereas MEP showed a positive association. Maternal MEOHP, ∑MEHP-3, and ∑MEHP-5 were positively associated with boys’ placenta weight, while MEOHP, MEHHP, 5cx-MEPP, ∑MEHP-3, and ∑MEHP-5 were negatively associated with girls’ placenta weight. Conclusions: Our findings suggest that parental exposure to phthalates at birth may adversely affect fetal growth and placental development in neonates. However, further studies with larger sample sizes and datasets are necessary.