title: Association between pre-eclampsia and locally derived traffic-related air pollution: a retrospective cohort study.
abstract: 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.
  
  
  METHODS
  The authors estimated maternal residential exposure to a marker for traffic-related air pollution (nitrogen dioxide, NO(2)) 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.
authors.affiliation: Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, Western Australia, Australia. pereirag@gmail.com
authors.forename: Gavin
authors.initials: G
authors.lastname: Pereira
authors.forename: Fatima
authors.initials: F
authors.lastname: Haggar
authors.forename: Antonia W
authors.initials: AW
authors.lastname: Shand
authors.forename: Carol
authors.initials: C
authors.lastname: Bower
authors.forename: Angus
authors.initials: A
authors.lastname: Cook
authors.forename: Natasha
authors.initials: N
authors.lastname: Nassar
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects* / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D016015:Logistic Models; D018811:Maternal Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D018986:Motor Vehicles; D009585:Nitrogen Dioxide / Q000032:analysis*; D011225:Pre-Eclampsia / Q000139:chemically induced / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011256:Pregnancy Outcome / Q000453:epidemiology; D011263:Pregnancy Trimester, Third; D012111:Residence Characteristics; D012189:Retrospective Studies; D012307:Risk Factors; D014505:Urban Population; D001335:Vehicle Emissions / Q000032:analysis / Q000633:toxicity*; D014904:Western Australia / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D001335:Vehicle Emissions; D009585:Nitrogen Dioxide