PFAS and gestational diabetes: Serum or plasma concentrations of PFAS have been associated with several health outcomes, including gestational diabetes mellitus (GDM).6–11 GDM increases risk among offspring of preterm birth and macrosomia,12 and, among mothers, of type 2 diabetes mellitus.13 In the U.S., the proportion of pregnant women who develop GDM has increased over the past ten years, possibly due to trends in risk factors such as obesity, but environmental factors could be contributing.14