Prenatal Exposure to Perfluoroalkyl Substances and Body Fatness in Girls

Background: Perfluoroalkyl substances (PFASs) are used in surface coatings that resist stains, grease, and water. Methods: The association between in utero PFAS exposure and girls' body fatness at age 9 was analyzed in The Avon Longitudinal Study of Parents and Children (UK). Maternal serum [median 15 weeks: interquartile range (IQR) 10 and 28 weeks of gestation] was analyzed for perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorohexane sulfonate (PFHxS), and perfluorononanoate (PFNA). Body composition was measured by dual X-ray emission absorptiometry, and percent total body fat (%BF) was calculated. Associations between PFASs and body fatness were modeled by multivariable linear regression. Results: Among 359 girls, median (IQR) %BF was 27.5 (IQR 21.7-34.6). Median (IQR) concentrations (all ng/mL) were 3.7 (2.9-4.8) for PFOA, 19.8 (15.0-25.3) for PFOS, 1.6 (1.3-2.2) for PFHxS, and 0.5 (0.4-0.7) for PFNA. Maternal PFAS concentrations were not significantly associated with daughters' total %BF overall. Mothers' educational status modified associations for PFOA and PFOS with %BF (P-interactions: 0.005 and 0.02, respectively). %BF was higher [1.4%; 95% confidence interval (95% CI): 0.3 to 2.5] for each one unit (ng/mL) higher PFOA among girls with mothers in the middle education group, but lower (-0.6%; 95% CI: -1.12 to -0.04) for the corresponding comparison among girls with mothers with the highest education. %BF was lower (-0.2%; 95% CI: -0.3 to -0.1) for each one unit higher PFOS among girls with the most educated mothers. Conclusions: Prenatal exposure to PFOA and PFOS was associated with girls' %BF within some strata of maternal education status. PFHxS and PFNA were not associated with %BF.