Gestational hypertension (GH) is a common complication during pregnancy. GH is regarded as a potential public health challenge for pregnant women and infants. Limited evidence has linked ambient air pollution to an increased GH risk. However, most of the studies were conducted in developed countries, with inconsistent results obtained. The present study was performed to explore whether exposure to particulate matters with an aerodynamic diameter < 2.5 (PM2.5) and ozone (O3) was related to elevated odds of GH in a Chinese population. This population-based cohort study involved 38 115 pregnant women in Wuhan, China. All information was collected from the Wuhan Maternal and Child Health Management Information System, using standardized quality control. The daily air pollutant data for PM2.5 and O3 were obtained from the 20 monitoring stations of the Wuhan Environmental Monitoring Center during 2014. The nearest monitor approach was applied to individual exposure assessment of PM2.5 and O3 for each participant. After adjusting for major confounders and other air pollutants, a 10 µg/m3 increase in PM2.5 and O3 concentrations was found to correlate to a 1.14-fold [95% confidence interval (95% CI): 1.09, 1.20] and a 1.05-fold (95% CI: 1.02, 1.07) increase in GH risk, respectively. Additionally, stronger relationships between GH risk and PM2.5 and O3 exposure were observed in women who conceived in winter and summer, respectively. These findings suggest that air pollutants may contribute to the development of GH.
Keywords: air pollution; fine particulate matter; gestational hypertension; hypertensive disorders of pregnancy; ozone.