Trimester-specific urinary bisphenol a concentrations and blood glucose levels among pregnant women from a fertility clinic

Context: Women with a history of infertility are at increased risk of impaired glucose tolerance during pregnancy. Studies suggest higher urinary bisphenol A (BPA) concentrations are associated with diabetes in nonpregnant populations, but the association between BPA and glucose levels among pregnant women is unclear. Objective: To assess trimester-specific urinary BPA concentrations in relation to blood glucose levels among subfertile women. Design: Environment and Reproductive Health Study, an ongoing prospective cohort study. Setting: A fertility center in a teaching hospital. Patients: A total of 245 women contributed at least one urine sample during first and/or second trimesters, delivered a singleton or twin pregnancy, and had available blood glucose data (2005 to 2015). Main Outcome Measure: Blood glucose levels after a nonfasting 50-g glucose challenge test at 24 to 28 weeks of gestation. Results: The specific gravity-adjusted geometric mean urinary BPA concentrations during first and second trimesters were 1.39 and 1.27 μg/L, respectively. Second-trimester BPA concentrations were positively associated with blood glucose (P, trend = 0.01). Specifically, the adjusted mean glucose levels (95% confidence interval) for women in the highest quartile of second-trimester BPA concentrations was 119 (112, 126) mg/dL compared with 106 (100, 112) mg/dL for women in the lowest quartile. No associations were observed between first-trimester BPA concentrations and glucose levels. Conclusions: BPA exposure during the second trimester may have adverse effect on blood glucose levels among subfertile women. As the findings represent the first report suggesting a potential etiologically relevant window for BPA and glucose in humans, further studies are needed.