Transplacental transfer of perfluorinated and poly-fluorinated substances in maternal-cord serum and association with birth weight: A birth cohort study, China.

Although the effects of traditional perfluorinated and polyfluorinated substances (PFASs) exposure have been extensively explored, research on novel PFASs remains limited, and there is a lack of data regarding their placental transfer and fetal impact. Herein, we aimed to examine maternal and fetal PFASs exposure levels, placental transfer efficiency (TTE), and the consequences of prenatal exposure on birth weight. The study included 214 mother-child pairs recruited in Wuxi birth cohort from 2019 to 2021. Twenty-three PFASs were quantified in maternal serum during the second trimester and umbilical serum during delivery. Median concentrations of ∑PFASs in maternal and cord sera were 9.34 and 6.88 ng/mL, respectively. The novel alternatives exhibited elevated levels of maternal and fetal exposure, such as perfluorovaleric acid (PFPeA, 2.00 ng/mL and 1.66 ng/mL, respectively) and perfluorohexane sulfonate (PFHxS, 1.77 and 1.14 ng/mL, respectively). With increasing carbon chain length, the TTE of perfluorocarbonic acid (PFCAs) displayed a pattern of initially decreasing before subsequently increasing, with novel alternatives exhibiting a relatively high TTE. Multiple linear regression showed that exposure to perfluorobutane sulfonate (PFBS) and PFPeA in cord serum positively correlated with the birth weight of female infants (β = 231.04 g, 95% confidence interval [CI]: 21.73-440.36; β = 121.26 g, 95% CI: 29.51-213.00). No nonlinear relationship was observed between cord serum PFASs and birth weight. The weighted quantile sum (WQS) regression analysis has reaffirmed that PFPeA and PFBS were predominant contributors to the positive correlation observed between the mixture of PFASs and birth weight. Our findings suggest that novel PFASs may exhibit a heightened susceptibility for transplacental transfer and that exposure to PFBS and PFPeA during pregnancy could be linked to increased birth weight.