PFOS, PFOA, estrogen homeostasis, and birth size in Chinese infants.

Laboratory studies have suggested that perfluoroalkyl substances (PFASs) could affect fetal growth by disrupting estrogen homeostasis, but there are limited data for human. For this, 424 mother-infant pairs were selected from a cohort established in Hebei Province of North China in 2013. Two typical PFASs, perfluorooctyl sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), and three typical estrogens, estrone (E1), β-estradiol (E2), and estriol (E3), were measured in cord serum. After adjusted for important covariates, serum PFOS was positively related to E1 and E3, but negatively related to E2. Serum PFOA was positively related to serum E1 and negatively related to head circumference at birth. Serum E2 was negatively related to head circumference, body weight, and body length at birth and serum E3 was positively related to body weight. Serum E3 mediated the relationship between serum PFOS and body weight. There were sex-specific differences for the associations between PFOS/PFOA and estrogens/birth size. These findings suggested that exposure to PFASs could affect estrogen homeostasis and fetal growth during pregnancy and that estrogens might mediate the association between exposure to PFASs and fetal growth.