Association of Seasonal Ambient Air Pollution With a Risk of Adverse Perinatal Outcomes in Full-term Pregnancies: A Retrospective Cohort Study in Wenzhou, China

Abstract Prenatal exposures to ambient air pollution have been proved to be associated with adverse perinatal outcomes in previous studies. However, few studies have examined the interaction between air pollution and season of conception on term low birth weight (TLBW) or macrosomia. Birth registry data of singleton live births in Wenzhou, China between January 2015 to December 2016 were accessed from the Wenzhou maternal and child health information management platform, and the ambient air pollutants in Wenzhou were obtained on the Chinese Air Quality Online Monitoring and Analysis Platform. Single/two-pollutant binary logistic regression models were used to assess the associations between ambient air pollutants (PM2.5, PM10, NO2, SO2, and O3) and TLBW/macrosomia, further exploring if the season of conception interacts with air pollution to impact birth weight. Finally, 213,959 term newborns were selected, including 2452 (1.1 %) TLBW infants and 13173 (6.1 %) macrosomia. In single/two-pollutant models, we observed an increased risk of TLBW associated with maternal exposure to PM2.5, PM10, SO2, and NO2 during the entire pregnancy, especially in the the 2nd trimester. Maternal exposure to O3 during the 1st trimester was associated with increased macrosomia risk, and O3 exposure during the 3rd trimester was associated with increased TLBW risk contrarily. Pregnant women conceived in the warm season may undergo more adverse ambient air environment that is related to the risks of TLBW.