OBJECTIVE Exposure to per- and polyfluoroalkyl substances (PFAS) may increase the risk of gestational diabetes mellitus (GDM), with adverse consequences for pregnant women and their offspring. However, epidemiologic studies have shown inconsistent results. We addressed this question in a large, pooled sample of U.S. women. RESEARCH DESIGN AND METHODS Participants (n = 5,229) from 16 cohorts had singleton pregnancies. PFAS were quantified in a single plasma or serum sample during pregnancy (1999–2021); six PFAS detected in ≥60% of participants were analyzed. The primary outcome was GDM diagnosis based on self-report or medical record documentation. The secondary outcome, among 1,213 participants, was fasting glucose. We estimated associations between each PFAS and GDM using generalized estimating equations models with Poisson distribution and robust variance, and estimated associations between each PFAS and fasting glucose using generalized estimating equations models for linear regression. Effect modification by prepregnancy BMI or race and ethnicity was evaluated via interaction terms and stratification. We quantified the combined effect of the PFAS mixture using quantile-based g-computation. RESULTS Associations between individual PFAS and GDM were null or weakly inverse; the association with the six-PFAS mixture was negative (prevalence ratio 95% CI per quartile increase: 0.75 0.58, 0.96). Certain PFAS were more strongly negatively associated with GDM among participants with BMI 25 kg/m2. Associations between PFAS and fasting glucose were largely null, although both positive and negative associations were observed in specific race and ethnicity strata. CONCLUSIONS In a large, pooled sample of U.S. pregnant women, greater concentrations of PFAS were not associated with higher prevalence of GDM.
Starling et al. (Tue,) studied this question.