Associations of prenatal per- and polyfluoroalkyl substances with whole blood folate levels in pregnant women in the Health Outcomes and Measures of the Environment (HOME) Study.

Background: Folate plays a critical role during pregnancy, preventing neural tube defects and possibly adverse neurodevelopment. Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals that may decrease folate levels. Although some studies have found associations between PFAS and folate, we are unaware of studies conducted in pregnant women. To address this knowledge gap, we evaluated associations between PFAS and whole blood folate (WBF) in pregnant women. Methods: We used data from 288 pregnant women in the Health Outcomes and Measures of the Environment (HOME) Study, a pregnancy and birth cohort in the Cincinnati Ohio area. We measured eight serum PFAS and WBF concentrations at 16 weeks' gestation. We used linear regression to estimate the effect of each PFAS on WBF, and quantile-based g-computation and Bayesian kernel machine regression (BKMR) to investigate the joint effect of PFAS on WBF, adjusting for parity, prenatal vitamin intake, maternal race/ethnicity, household income, maternal age, and second trimester smoking status in all models. In addition, we investigated interactions between PFAS using BKMR. Results: We did not observe inverse associations of individual PFAS or their mixture with WBF, nor interactions between PFAS in the BKMR model in pregnant women. Conclusion: Future studies could consider WBF measures in late pregnancy to evaluate other periods of susceptibility. Furthermore, as people are exposed to multiple PFAS, future studies should continue to consider joint PFAS exposure.