title: Ambient air pollution and pregnancy-induced hypertensive disorders: a systematic review and meta-analysis.
abstract: Pregnancy-induced hypertensive disorders can lead to maternal and perinatal morbidity and mortality, but the cause of these conditions is not well understood. We have systematically reviewed and performed a meta-analysis of epidemiological studies investigating the association between exposure to ambient air pollution and pregnancy-induced hypertensive disorders including gestational hypertension and preeclampsia. We searched electronic databases for English language studies reporting associations between ambient air pollution and pregnancy-induced hypertensive disorders published between December 2009 and December 2013. Combined risk estimates were calculated using random-effect models for each exposure that had been examined in ≥4 studies. Heterogeneity and publication bias were evaluated. A total of 17 articles evaluating the impact of nitrogen oxides (NO2, NOX), particulate matter (PM10, PM2.5), carbon monoxide (CO), ozone (O3), proximity to major roads, and traffic density met our inclusion criteria. Most studies reported that air pollution increased risk for pregnancy-induced hypertensive disorders. There was significant heterogeneity in meta-analysis, which included 16 studies reporting on gestational hypertension and preeclampsia as separate or combined outcomes; there was less heterogeneity in findings of the 10 studies reporting solely on preeclampsia. Meta-analyses showed increased risks of hypertensive disorders in pregnancy for all pollutants except CO. Random-effect meta-analysis combined odds ratio associated with a 5-μg/m3 increase in PM2.5 was 1.57 (95% confidence interval, 1.26-1.96) for combined pregnancy-induced hypertensive disorders and 1.31 (95%confidence interval, 1.14-1.50) for preeclampsia [corrected]. Our results suggest that exposure to air pollution increases the risk of pregnancy-induced hypertensive disorders.
authors.affiliation: From the Centre for Research in Environmental Epidemiology, Barcelona, Spain (M.P., L.S., M.J.N., P.D.); CIBER Epidemiología y Salud Pública, Madrid, Spain (M.P., M.J.N., P.D.); Universitat Pompeu Fabra, Barcelona, Spain (M.P., M.J.N., P.D.); INSERM, U823, Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute Albert Bonniot, Grenoble, France (M.P., R.S.); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago (L.S.); University Joseph Fourier, Institute Albert Bonniot, Grenoble, France (R.S.); Danish Cancer Society Research Center, Copenhagen, Denmark (M.S., O.R.-N.); and Department of Maternal-Foetal Medicine, ICGON, Hospital Clinic IDIBAPS, University of Barcelona, Barcelona, Spain (F.F.). mpedersen@creal.cat.
authors.forename: Marie
authors.initials: M
authors.lastname: Pedersen
authors.affiliation: From the Centre for Research in Environmental Epidemiology, Barcelona, Spain (M.P., L.S., M.J.N., P.D.); CIBER Epidemiología y Salud Pública, Madrid, Spain (M.P., M.J.N., P.D.); Universitat Pompeu Fabra, Barcelona, Spain (M.P., M.J.N., P.D.); INSERM, U823, Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute Albert Bonniot, Grenoble, France (M.P., R.S.); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago (L.S.); University Joseph Fourier, Institute Albert Bonniot, Grenoble, France (R.S.); Danish Cancer Society Research Center, Copenhagen, Denmark (M.S., O.R.-N.); and Department of Maternal-Foetal Medicine, ICGON, Hospital Clinic IDIBAPS, University of Barcelona, Barcelona, Spain (F.F.).
authors.forename: Leslie
authors.initials: L
authors.lastname: Stayner
authors.affiliation: From the Centre for Research in Environmental Epidemiology, Barcelona, Spain (M.P., L.S., M.J.N., P.D.); CIBER Epidemiología y Salud Pública, Madrid, Spain (M.P., M.J.N., P.D.); Universitat Pompeu Fabra, Barcelona, Spain (M.P., M.J.N., P.D.); INSERM, U823, Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute Albert Bonniot, Grenoble, France (M.P., R.S.); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago (L.S.); University Joseph Fourier, Institute Albert Bonniot, Grenoble, France (R.S.); Danish Cancer Society Research Center, Copenhagen, Denmark (M.S., O.R.-N.); and Department of Maternal-Foetal Medicine, ICGON, Hospital Clinic IDIBAPS, University of Barcelona, Barcelona, Spain (F.F.).
authors.forename: Rémy
authors.initials: R
authors.lastname: Slama
authors.affiliation: From the Centre for Research in Environmental Epidemiology, Barcelona, Spain (M.P., L.S., M.J.N., P.D.); CIBER Epidemiología y Salud Pública, Madrid, Spain (M.P., M.J.N., P.D.); Universitat Pompeu Fabra, Barcelona, Spain (M.P., M.J.N., P.D.); INSERM, U823, Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute Albert Bonniot, Grenoble, France (M.P., R.S.); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago (L.S.); University Joseph Fourier, Institute Albert Bonniot, Grenoble, France (R.S.); Danish Cancer Society Research Center, Copenhagen, Denmark (M.S., O.R.-N.); and Department of Maternal-Foetal Medicine, ICGON, Hospital Clinic IDIBAPS, University of Barcelona, Barcelona, Spain (F.F.).
authors.forename: Mette
authors.initials: M
authors.lastname: Sørensen
authors.affiliation: From the Centre for Research in Environmental Epidemiology, Barcelona, Spain (M.P., L.S., M.J.N., P.D.); CIBER Epidemiología y Salud Pública, Madrid, Spain (M.P., M.J.N., P.D.); Universitat Pompeu Fabra, Barcelona, Spain (M.P., M.J.N., P.D.); INSERM, U823, Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute Albert Bonniot, Grenoble, France (M.P., R.S.); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago (L.S.); University Joseph Fourier, Institute Albert Bonniot, Grenoble, France (R.S.); Danish Cancer Society Research Center, Copenhagen, Denmark (M.S., O.R.-N.); and Department of Maternal-Foetal Medicine, ICGON, Hospital Clinic IDIBAPS, University of Barcelona, Barcelona, Spain (F.F.).
authors.forename: Francesc
authors.initials: F
authors.lastname: Figueras
authors.affiliation: From the Centre for Research in Environmental Epidemiology, Barcelona, Spain (M.P., L.S., M.J.N., P.D.); CIBER Epidemiología y Salud Pública, Madrid, Spain (M.P., M.J.N., P.D.); Universitat Pompeu Fabra, Barcelona, Spain (M.P., M.J.N., P.D.); INSERM, U823, Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute Albert Bonniot, Grenoble, France (M.P., R.S.); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago (L.S.); University Joseph Fourier, Institute Albert Bonniot, Grenoble, France (R.S.); Danish Cancer Society Research Center, Copenhagen, Denmark (M.S., O.R.-N.); and Department of Maternal-Foetal Medicine, ICGON, Hospital Clinic IDIBAPS, University of Barcelona, Barcelona, Spain (F.F.).
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Nieuwenhuijsen
authors.affiliation: From the Centre for Research in Environmental Epidemiology, Barcelona, Spain (M.P., L.S., M.J.N., P.D.); CIBER Epidemiología y Salud Pública, Madrid, Spain (M.P., M.J.N., P.D.); Universitat Pompeu Fabra, Barcelona, Spain (M.P., M.J.N., P.D.); INSERM, U823, Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute Albert Bonniot, Grenoble, France (M.P., R.S.); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago (L.S.); University Joseph Fourier, Institute Albert Bonniot, Grenoble, France (R.S.); Danish Cancer Society Research Center, Copenhagen, Denmark (M.S., O.R.-N.); and Department of Maternal-Foetal Medicine, ICGON, Hospital Clinic IDIBAPS, University of Barcelona, Barcelona, Spain (F.F.).
authors.forename: Ole
authors.initials: O
authors.lastname: Raaschou-Nielsen
authors.affiliation: From the Centre for Research in Environmental Epidemiology, Barcelona, Spain (M.P., L.S., M.J.N., P.D.); CIBER Epidemiología y Salud Pública, Madrid, Spain (M.P., M.J.N., P.D.); Universitat Pompeu Fabra, Barcelona, Spain (M.P., M.J.N., P.D.); INSERM, U823, Team of Environmental Epidemiology Applied to Reproduction and Respiratory Health, Institute Albert Bonniot, Grenoble, France (M.P., R.S.); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago (L.S.); University Joseph Fourier, Institute Albert Bonniot, Grenoble, France (R.S.); Danish Cancer Society Research Center, Copenhagen, Denmark (M.S., O.R.-N.); and Department of Maternal-Foetal Medicine, ICGON, Hospital Clinic IDIBAPS, University of Barcelona, Barcelona, Spain (F.F.).
authors.forename: Payam
authors.initials: P
authors.lastname: Dadvand
mesh_terms: D000328:Adult; D000397:Air Pollution / Q000009:adverse effects*; D002248:Carbon Monoxide / Q000009:adverse effects; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000453:epidemiology* / Q000209:etiology; D009589:Nitrogen Oxides / Q000009:adverse effects; D010126:Ozone / Q000009:adverse effects; D052638:Particulate Matter / Q000009:adverse effects*; D011225:Pre-Eclampsia / Q000453:epidemiology / Q000209:etiology; D011247:Pregnancy; D012307:Risk Factors
chemical_list: D009589:Nitrogen Oxides; D052638:Particulate Matter; D010126:Ozone; D002248:Carbon Monoxide
keywords: air pollution; hypertension, pregnancy-induced; pre-eclampsia; pregnancy