Per- and polyfluoroalkyl substances (PFAS) were not associated with higher gestational diabetes mellitus (GDM) prevalence in a large pooled analysis of U.S. cohorts. A study published in Diabetes Care evaluated the relationship between PFAS exposure during pregnancy and GDM, addressing inconsistent findings from prior epidemiologic studies.

The analysis included 5,229 pregnant women from 16 cohorts with singleton pregnancies between 1999 and 2021. PFAS concentrations were measured in plasma or serum samples during pregnancy, and six PFAS detected in at least 60% of participants were analyzed. GDM diagnosis was based on self-report or medical record documentation, and fasting glucose was assessed in a subset of 1,213 participants.

Generalized estimating equations models with Poisson distribution and robust variance were used to estimate associations between PFAS and GDM, while linear regression models evaluated associations with fasting glucose. Effect modification by prepregnancy body mass index (BMI) and race and ethnicity was examined, and mixture effects were assessed using quantile-based g-computation.

Associations between individual PFAS and GDM were null or weakly inverse. The PFAS mixture showed an inverse association with GDM (prevalence ratio 0.75 per quartile increase; 95% confidence interval 0.58-0.96). In subgroup analyses, inverse associations were more pronounced among individuals with prepregnancy BMI below 25 kg/m².

Associations between PFAS and fasting glucose were largely null, although both positive and negative patterns were observed across race and ethnicity strata. PFAS exposure during pregnancy did not show an increased prevalence of GDM in this pooled U.S. cohort.