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

Summary

Among 770 primiparous pregnant women, 289 developed gestational diabetes mellitus (GDM). High reported microplastic exposure was associated with increased GDM risk versus low exposure (OR 2.19, 95% CI 1.46–3.28; p<0.001), with particularly strong associations for makeup and personal-care products.

Key Findings

• The prospective cohort included 770 primiparous pregnant women, of whom 289 (37.5%) developed GDM.
• GDM prevalence was 55.9% in the high-exposure group versus 36.6% in the low-exposure group.
• High exposure was associated with GDM versus low exposure with OR 2.19 (95% CI 1.46–3.28; p<0.001), with the strongest product-level signals involving makeup and personal-care items.

Clinical Implications

Clinicians may consider discussing reduction of avoidable cosmetic and personal-care product exposures with pregnant patients, but the findings do not yet justify formal exposure restrictions because exposure was self-reported and causality was not established.

Limitations

• Microplastic exposure was assessed by questionnaire rather than by biomonitoring or direct chemical measurements.
• Residual confounding, recall bias, and the possibility of reverse or noncausal associations cannot be excluded.

Future Directions

Future studies should use longitudinal biomonitoring of specific polymers and additives, clarify dermal versus dietary exposure pathways, replicate findings in diverse populations, and test whether exposure reduction lowers GDM incidence.