Fig 2. Monthly associations between maternal exposure to PM_2.5 during pregnancy and hypertensive disorders of pregnancy.

N = 373,905 for GH cohort; N = 386,361 for PE-E cohort. HRs and 95% CIs were calculated for per IQR increment for each air pollutant. Models adjusted for maternal age, race/ethnicity, education, household income, smoking and passive smoking status during pregnancy, parity, insurance type, season, and year of infant birth. CI, confidence interval; GH, gestational hypertension; HR, hazard ratio; IQR, interquartile range; PE-E, preeclampsia-eclampsia.