Peri-conceptional exposure to ambient air pollution increases risk of gestational diabetes among pregnant participants in the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) study

Abstract

Background: Exposures to air pollution potentially disrupt maternal metabolic adaptation during pregnancy. However, influences of preconception and prenatal exposures to ambient air pollution on gestational diabetes mellitus (GDM) remain unclear, and even less is known about sensitive windows for these exposures’ effect on GDM. Methods: In 617 pregnant participants enrolled the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) study, we estimated daily levels of ambient particulate matter (PM₁₀; PM₂.₅), nitrogen dioxide (NO₂), ozone (O₃) using spatial interpolation. GDM was ascertained from medical records by physician diagnosis or defined as abnormally high glucose challenge and tolerance test results. We used distributed lag models (DLM) with Poisson regression to identify sensitive exposure windows by estimating weekly associations of exposures from pre-conception week (PcW) 12 to gestational week (GW) 24 with GDM risk, adjusting for maternal and meteorological factors. Analyses were additionally stratified by median prenatal Perceived Stress Scale (PSS, 14), median pre-pregnancy body mass index (BMI, 27.5 kg/m²), median age (28 years), and newborn sex to explore differential susceptibility to exposure effects. Results: Sixty (9.7%) participants were diagnosed with GDM. We identified sensitive peri-conceptional exposure windows for PM₂.₅, PM₁₀, and NO₂ ranging from PcW5 to GW3 associated with increased GDM risk. An IQR increase in each pollutant was associated with 5% (95%CI: 3.3-6.7%), 6% (5.9-7.4%), and 11% (9.3-12.2%) increased GDM risk, respectively. In stratified analyses, effects of PM₁₀ and NO₂ in the identified sensitive windows were greater among those ≥28 years old, with BMI≥27.5 kg/m², or with PSS≥14. Conclusions: Peri-conception exposures to ambient air pollutants were associated with increased risk of GDM. Stronger effects in the identified sensitive windows were seen in participants who were older, had higher BMI, or higher perceived stress. Keywords: air pollution, gestational diabetes, sensitive window, susceptibility, perceived stress, preconception