Dose-dependent association of prenatal microplastic exposure with gestational diabetes Mellitus: A prospective cohort...

This study aimed to elucidate the potential crosslink between microplastic exposure and the development of Gestational Diabetes Mellitus (GDM) in primiparous pregnant women.

Prospective cohort study, involved 770 pregnant women. Data on demographic factors and microplastic exposure assessed through a validated Microplastic Exposure Questionnaire (MEQ) were collected, focusing on exposure via cosmetics, toiletries, and food. Participants were categorized into low (≤ 113), moderate (114-142), and high (≥ 143) exposure groups based on quartile-derived thresholds (Q1 = 113, Q3 = 142). Content Validity index and Cronbach's alpha reliability test were performed to ensure the reliability and validity of the questionnaire. Primary outcome assessed for the incidence of GDM.

The Cronbach's alpha value was 0.835, indicating good internal consistency. Scale Content Validity Index (S-CVI/Ave) results indicated that the questionnaire has moderate to strong content validity. Among the 770 participants, 289 (37.5%) were diagnosed with GDM, while 481 (62.5%) were non-GDM. Exposure distribution revealed 202 women with low exposure (74 GDM, 128 non-GDM, 36.6% GDM prevalence), 380 with moderate exposure (110 GDM, 270 non-GDM, 28.9% GDM prevalence), and 188 with high exposure (105 GDM, 83 non-GDM, 55.9% GDM prevalence). Chi-square analysis indicated a significant association between microplastic exposure category and GDM status (χ² = 38.92, df = 2, p < 0.001). Binary logistic regression demonstrated that high exposure significantly increased GDM risk compared to low exposure (OR = 2.19, 95% CI: 1.46-3.28, p < 0.001), whereas moderate exposure was not significant (OR = 0.71, 95% CI: 0.49-1.01, p = 0.058). Sub-category analysis revealed strongest links in makeup products (90.9% significant items; Cramér's V up to 0.191) and personal care/toiletries (62.5%; V up to 0.367), exceeding dietary habits.

High maternal microplastic exposure is significantly associated with increased GDM risk in pregnant women, suggesting that microplastic exposure may represent a novel risk factor for GDM. Public health interventions should prioritize reducing dermal exposure from cosmetics and personal care products.