Effects of Endocrine Disrupting Chemicals on Fetal Weight: Exposure Monitoring Among Mothers with Gestational Diabetes Mellitus and Their Fetuses

Gestational diabetes mellitus (GDM) requires lifestyle changes that may alter exposure to endocrine-disrupting chemicals (EDCs). This study aimed to assess maternal and fetal exposure to EDCs—including bisphenol-A (BPA), monoethyl phthalate (MEP), and perfluorooctanoic acid (PFOA)—during the COVID-19 pandemic and to evaluate their association with fetal birthweight. Maternal urine (second and third trimester) and paired cord blood samples were analyzed from 58 GDM and 118 non-GDM pregnancies using UPLC-MS/MS. Significant correlations were found between maternal urine and cord blood levels of BPA and MEP. Cord blood BPA levels were significantly lower in GDM mothers (0.35 vs. 0.72 μg/L, p < 0.05), suggesting reduced exposure due to dietary interventions. However, maternal urinary BPA levels in GDM pregnancies were positively associated with fetal birthweight (β = 2.69, p < 0.05), indicating increased susceptibility to obesogenic effects. PFOA was present in all cord blood but only 41% of maternal urine samples. These findings underscore the dual impact of GDM-related lifestyle changes: reduced EDC transfer to the fetus, yet persistent metabolic vulnerability.