Ambient Fine Particulate Matter, Nitrogen Dioxide, and Hypertensive Diseases of Pregnancy in New York City

Abstract

Along with growing evidence of a possible effect of urban air pollution on fetal growth and preterm birth, there is a possible impact on hypertensive disorders of pregnancy. Some but not all recent studies have yielded evidence suggesting an impact of both fine particulate matter and nitrogen dioxide. To address limitations in exposure and outcome assessment and study size, we analyzed a unique data resource from New York City. Birth certificate information on 268,601 New York City residents delivering 2008-2010 was linked to hospital discharge data to more accurately identify gestational hypertension and preeclampsia (classified as mild or severe). Exposure to air pollution was assigned based on residential location linked to monitoring data from the New York City Community Air Survey, conducted specifically to characterize air pollution exposure. Adjusting for covariates from the birth records, we analyzed the association between first and second trimester fine particulate matter and nitrogen dioxide in relation to hypertensive disorders using multinomial logistic regression. While partially adjusted analyses yielded adjusted odds ratios in the highest quartile of exposure (compared to the lowest) of 1.3-1.6 for gestational hypertension and 0.8-0.9 for mild preeclampsia, we identified that rates of disorders differed by hospital and were associated with pollution levels of their patients. Adjustment for hospital yielded null results for all outcomes, indicating no association between ambient air pollution and hypertensive disorders of pregnancy.