Exposure to persistent organic pollutants in Danish pregnant women: Hormone levels and fetal growth indices.

This study examines possible associations of maternal Persistent Organic Pollutants (POP) exposure during pregnancy, maternal hormone levels and fetal growth indices (FGI). During 1st trimester, we measured maternal thyroids, androgens and estrogens, lipophilic POP and perfluorinated-alkyl-acid (PFAA) levels in serum from nulliparous women. Adjusted multivariate-linear regression models assessed associations between exposure and outcomes. Maternal characteristics and POP exposures associated with maternal hormone levels. Lipophilic POP elicited inverse association with androgen and estrogen levels but no strong association with thyroids. Higher level of PFAA was associated with higher thyroid and androgen levels. The PFAA did not associate with estrogens. Higher thyroid-peroxidase-antibody (TPO-Ab) and estradiol level associated with higher birth weight and length in sons. For daughters, the TPO-Ab associations were the opposite being inversely associated with birth weight and length, and higher TPO-Ab and estradiol associated with lower gestational age. Mediation analyses suggested that TPO-Ab mediates the association of PFAA with FGI.