Association BetweenPM2.5Exposure and Preeclampsia

Abstract

Background: Previous studies have suggested that traffic-related air pollution can increase risk of pregnancy complications. The purpose of this research is to investigate if PM2.5 exposure one year prior to conception is associated with preeclampsia. Methods: We obtained all live and still births from the Massachusetts state birth registry with an estimated conception date between January 2002 through December 2008. We randomly selected 2,000 infants conceived each year to serve as the study population. Of those 14,000 births, all mothers diagnosed with the main symptoms of preeclampsia, high blood pressure or proteinuria, were identified as cases. Cumulative PM2.5 exposure was assessed using 4-km spatial satellite remote sensing, meteorological and land use spatiotemporal models at geocoded birth addresses for the year prior to conception. We calculated crude and adjusted preeclampsia odds ratios (ORs) and 95% confidence intervals (CI) per 10 µg/m3 increase of PM2.5 exposure. Analyses of complete data were adjusted for demographic, socioeconomic, and reproductive characteristics of the mother. Births missing over 70% of PM2.5 data were excluded. Results: Our final analyses included 576 cases and 11,679 controls. Cumulative PM2.5 exposure during the year prior to conception was not associated with preeclampsia in the unadjusted analyses (OR: 1.02; 95%CI: 0.97,1.07). After adjusting for maternal age, race, education, language, insurance status, parity, smoking, drinking, adequacy of care, and year of birth, PM2.5 exposure remained not significantly associated with preeclampsia (OR: 1.04; 95%CI: 0.98,1.10). As confirmed by prior literature, Non-Hispanic Black mothers had almost double the risk of being a case compared to the referent group (Non-Hispanic White) (OR: 1.89; 95%CI: 1.44,2.48). Discussion: We did not find evidence to support the relationship between maternal traffic related air pollution exposure and preeclampsia. Future work will assess whether other areas with a higher threshold of air pollution exposure would be associated with preeclampsia.