LAUSR

Perfluoroalkyl substances (PFAS) are chemicals used in the manufacture of consumer products. PFAS may act as endocrine disruptors, influencing metabolic pathways and weight-related outcomes. We analyzed associations of maternal serum pregnancy concentrations of PFAS with gestational weight gain (GWG). We used data from 905 women in a subsample of the Avon Longitudinal Study of Parents and Children. Women were routinely weighed in antenatal check-ups; absolute GWG was determined by subtracting the first weight measurement from the last. Linear regression was used to explore associations of maternal PFAS concentrations with absolute GWG, stratified by pre-pregnancy body mass index. Associations of maternal PFAS concentrations with absolute GWG were null. Ten percent higher perfluorooctane sulfonic acid (PFOS) was associated with GWG of -0.03kg (95% CI: -0.11, 0.06) and -0.12kg (95% CI: -0.30, 0.06) among under-/normal weight and overweight/obese mothers, respectively. Overall, findings suggest no association between maternal PFAS concentrations and GWG.