A recent retrospective cohort study of 33,060 first-time pregnancies from 2017 to 2022 highlights critical links between environmental air pollution, gestational diabetes mellitus (GDM), and birth weight outcomes. While air pollution exposure is long known to affect birth weight, this study explored specifically how GDM influences this relationship, providing new insights into vulnerable maternal subgroups.
Study Methods and Findings
The research utilised satellite-based estimates of air pollutants including PM2.5, PM10, NO2, CO, and O3 to measure maternal exposure during different trimesters. Multilevel logistic regression models, accounting for individual factors and season of conception, were used to identify associations with both low birth weight (LBW) and macrosomia. The study importantly revealed that air pollution exposure increased the risk for both LBW and macrosomia. Moreover, in patients with GDM, exposure during specific pregnancy periods significantly elevated the risk of macrosomia. For example, GDM moderated the effect of PM2.5 and NO2 exposure in the first trimester on LBW risk and influenced the relationships between various pollutants and macrosomia risks across all three trimesters.
Implications for Maternal and Newborn Health
These findings underscore the compounded risks faced by pregnant women with GDM when exposed to pollution and suggest targeted protection strategies for this susceptible group. By confirming that GDM significantly moderates the detrimental effects of air pollution on birth weight, the study emphasises the urgent need for public health interventions focusing on environmental and metabolic factors during pregnancy. Protecting maternal and fetal health requires addressing both air quality and gestational diabetes management to reduce adverse birth outcomes.
This study adds a crucial dimension to understanding how environmental and health factors interact during pregnancy, supporting policies aimed at lowering pregnant women’s exposure to harmful air pollutants, especially those with underlying metabolic vulnerabilities like GDM.
Reference
Fan Z et al. Air pollution exposure during pregnancy and low birth weight and macrosomia: the role of gestational diabetes mellitus. Reproductive Health. 2025;22:208.
