Association between pre-eclampsia and locally derived traffic-related air pollution: a retrospective cohort study
- 1Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, Western Australia, Australia
- 2School of Population Health, The University of Western Australia, Perth, Western Australia, Australia
- 3Perinatal Research, Kolling Institute of Medical Research, University of Sydney, Royal North Shore Hospital, Sydney, New South Wales, Australia
- 4Department of Obstetrics, Royal Hospital for Women, Sydney, New South Wales, Australia
- Correspondence to Dr Gavin Pereira, Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, 100 Roberts Road, Subiaco WA 6008, Australia;
Contributors GP was involved in the conceptual design, conducting analysis, interpretation of the results and writing of the paper. FG, AS, AC, CB and NN were involved in the conceptual design, revisions of the paper and interpretation of results.
- Accepted 9 July 2012
- Published Online First 9 August 2012
Background Pre-eclampsia is a common complication of pregnancy and is a major cause of fetal–maternal mortality and morbidity. Despite a number of plausible mechanisms by which air pollutants might contribute to this process, few studies have investigated the association between pre-eclampsia and traffic emissions, a major contributor to air pollution in urban areas.
Objective The authors investigated the association between traffic-related air pollution and risk of pre-eclampsia in a maternal population in the urban centre of Perth, Western Australia.
Method The authors estimated maternal residential exposure to a marker for traffic-related air pollution (nitrogen dioxide, NO2) during pregnancy for 23 452 births using temporally adjusted land-use regression. Logistic regression was used to investigate associations with pre-eclampsia.
Results Each IQR increase in levels of traffic-related air pollution in whole pregnancy and third trimester was associated with a 12% (1%–25%) and 30% (7%–58%) increased risk of pre-eclampsia, respectively. The largest effect sizes were observed for women aged younger than 20 years or 40 years or older, aboriginal women and women with pre-existing and gestational diabetes, for whom an IQR increase in traffic-related air pollution in whole pregnancy was associated with a 34% (5%–72%), 35% (0%–82%) and 53% (7%–219%) increase in risk of pre-eclampsia, respectively.
Conclusions Elevated exposure to traffic-related air pollution in pregnancy was associated with increased risk of pre-eclampsia. Effect sizes were highest for elevated exposures in third trimester and among younger and older women, aboriginal women and women with diabetes.
- Air pollution
- vehicle emissions
- pregnancy outcome
- land-use regression
Funding CB is supported by an Australian National Health and Medical Research Council (NHMRC) Principal Research Fellowship (634341) and NN by an NHMRC Career Development Fellowship (632955). The funding sources had no role in the design, conduct or reporting of the study or in the decision to submit the manuscript for publication.
Competing interests None.
Ethics approval Ethics approval was provided by the University of Western Australia and the Western Australian Department of Health.
Provenance and peer review Not commissioned; externally peer reviewed.