title: Ambient Air Pollution and Hypertensive Disorders of Pregnancy: A Systematic Review and Meta-analysis.
abstract: Hypertensive disorders of pregnancy (HDP, including gestational hypertension, preeclampsia, and eclampsia) have a substantial public health impact. Maternal exposure to high levels of air pollution may trigger HDP, but this association remains unclear. The objective of our report is to assess and quantify the association between maternal exposures to criteria air pollutants (ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter ≤ 10, 2.5 μm) on HDP risk. PubMed, EMBASE, MEDLINE, Current Contents, Global Health, and Cochrane were searched (last search: September, 2013). After a detailed screening of 270 studies, 10 studies were extracted. We conducted meta-analyses if a pollutant in a specific exposure window was reported by at least four studies. Using fixed- and random-effects models, odds ratios (ORs) and 95% CIs were calculated for each pollutant with specific increment of concentration. Increases in risks of HDP (OR per 10 ppb = 1.16; 95% CI, 1.03-1.30) and preeclampsia (OR per 10 ppb = 1.10; 95% CI, 1.03-1.17) were observed to be associated with exposure to NO2during the entire pregnancy, and significant associations between HDP and exposure to CO (OR per 1 ppm = 1.79; 95% CI, 1.31-2.45) and O3(OR per 10 ppb = 1.09; 95% CI, 1.05-1.13) during the first trimester were also observed. Our review suggests an association between ambient air pollution and HDP risk. Although the ORs were relatively low, the population-attributable fractions were not negligible given the ubiquitous nature of air pollution.
authors.affiliation: Department of Epidemiology, College of Public Health and Health Professions, University of Florida.
authors.forename: Hui
authors.initials: H
authors.lastname: Hu
authors.affiliation: Department of Epidemiology, College of Public Health and Health Professions, University of Florida.
authors.forename: Sandie
authors.initials: S
authors.lastname: Ha
authors.affiliation: Department of Pediatrics, College of Medicine, University of Florida.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Roth
authors.affiliation: Department of Public Health, Brody School of Medicine, East Carolina University.
authors.forename: Greg
authors.initials: G
authors.lastname: Kearney
authors.affiliation: Department of Epidemiology, School of Public Health, University of Pittsburgh.
authors.forename: Evelyn O
authors.initials: EO
authors.lastname: Talbott
authors.affiliation: Department of Epidemiology, College of Public Health and Health Professions, University of Florida.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Xu
keywords: air pollution; gestational hypertension; hypertensive disorders of pregnancy; meta-analysis; preeclampsia; pregnancy-induced hypertension