Association between Exposure to Per- and Polyfluoroalkyl Substances (PFAS) during Pregnancy and Biomarkers of Stress Response in the Maternal-Fetal Unit

Abstract

In a demographically diverse cohort of 500 pregnant women recruited from two San Francisco hospitals, we used linear regression to evaluate the association between eight PFAS with detection frequency of 50% or greater in our sample, and two biological measures of stress response: 1) telomere length (TL) in umbilical cord blood leukocytes collected at delivery, and 2) corticotropin-releasing hormone (CRH) in maternal plasma collected during the 2nd trimester. Both outcomes were log-transformed. PFAS levels (ug/L) were measured in mother’s serum during the 2nd trimester, and also log-transformed. Each chemical was assessed separately since levels were highly correlated. CRH analyses were adjusted for pregnancy complications, mother’s age, parity, and race/ethnicity. TL analyses were additionally adjusted for infant sex, and gestational age at birth. We also evaluated the associations separately for Latina and White women.The burden of PFAS exposure was greater among Latinas (30% of participants) than White women (40% of participants) in our study population. PFAS were not associated with TL, expressed as the relative ratio of telomere repeat copy number to single-copy gene copy number. A one unit increase in Perfluoroundecanoic acid (PFUdA) was associated with a 0.14 increase in CRH in race adjusted models (95% CI: 0.04–0.23). Higher levels of Perfluorononanoic acid (PFNA; 0.25, 95% CI: 0.07-0.44), Perfluorooctanesulfonic acid (PFOS; 0.161, 95% CI: 0.003-0.32), 2-(N-Methyl-perfluorooctane sulfonamido) acetic acid (MePFOSAAchOH; 0.18, 95% CI: 0.03-0.34), Perfluorohexane sulfonic acid (PFHxS; 0.20, 95% CI: 0.02-0.38), and PFUdA (0.38, 95% CI: 0.19–0.57) were all significantly associated with higher CRH among Latinas. Higher levels of Perfluorooctanesulfonamide (PFOSA; 0.07, 95% CI: 0.01-0.15) were significantly associated with higher CRH among white women. Results suggest complex relationships between prenatal PFAS exposure and stress response biomarkers.