THE ASSOCIATION BETWEEN EXPOSURE TO AIR POLLUTANTS AND GESTATIONAL HYPERTENSION IN WOMEN RESIDING IN URBAN HALIFAX

Abstract

This population-based retrospective cohort study examined the relationship between exposure to air pollution during pregnancy and gestational hypertension (GH). The Atlee Perinatal Database was used to determine GH and potential covariates. Spatial estimates of air pollution were determined from land-use regression models. National Air Pollution Surveillance estimates were used for temporal adjustment. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression. Of 11,724 singleton births analyzed, 7.7% of mothers developed GH. Significant inverse relationships were observed between GH and exposure to all pollutants (top quartile of exposure relative to lowest quartile); SO2 (OR: 0.75; 95% CI: 0.62, 0.92), NO2 (0.66; 0.54, 0.81), PM1 (0.71; 0.57, 0.87), PM2.5 (0.68, 0.56, 0.83), PM10 (0.71; 0.58, 0.87) toluene (0.68; 0.56, 0.83) and benzene (0.62; 0.51, 0.75). The inverse relationships could be a true protective effect or due to an unknown confounding factor coupled with a weak signal. A better understanding of the characteristics that influence the relationship between air pollution and GH may explain the observed results.