Abstract
Background: Preeclampsia is a major complication of pregnancy that can lead to substantial maternal and perinatal morbidity, mortality, and preterm birth. Increasing evidence suggests that air pollution adversely affects pregnancy outcomes. Yet few studies have examined how local traffic generated emissions affect preeclampsia in addition to preterm birth. Objectives: We examined effects of residential exposure to local traffic-generated air pollution on preeclampsia and preterm delivery (PTD). Methods: We identified 81,186 singleton birth records from four hospitals (1997-2006) in Los Angeles and Orange Counties, California (USA). We used a line source dispersion model (CALINE4) to estimate individual exposure to local traffic-generated nitrogen oxides (NO_x ) and particulate matter ¡ 2.5 𝜇m in aerodynamic diameter (PM_2.5 ) across the entire pregnancy. We used logistic regression to estimate effects of air pollution exposures on preeclampsia. PRD (gestational age ¡ 37 weeks), moderate PTD (MPTD; gestational age ¡ 35 weeks), and very PTD (VPTD; gestational age ¡ 30 weeks). Results: We observed elevated risks for preeclampsia and preterm birth from maternal exposure to local traffic-generated NO_x and PM_2.5 . The risk of preeclampsia increased 33