title: Fine particulate matter and risk of preterm birth and pre-labor rupture of membranes in Perth, Western Australia 1997-2007: a longitudinal study.
abstract: OBJECTIVE
  A recent longitudinal study reported an association between fine particulate (PM2.5) exposure and preterm birth (PTB) in a US cohort. We applied the same design to an Australian cohort to investigate associations with PTB and pre-labor rupture of membranes (PROM).
  
  
  METHODS
  From 287,680 births, we selected 39,189 women who had singleton births at least twice in Western Australia in 1997-2007 (n=86,844 births). Analyses matched pregnancies to the same women with conditional logistic regression.
  
  
  RESULTS
  For PROM adjusted odds ratios (ORs) for a 1 μg/m(3) increase in PM2.5 in the first trimester, second trimester, third trimester, and whole pregnancy were 1.00 (95% confidence interval (CI): 0.97, 1.03), 1.03 (95% CI: 1.00, 1.06), 1.02 (95% CI: 1.00, 1.05), and 1.02 (95% CI: 0.99, 1.05) respectively. For PTB, corresponding ORs were 1.00 (95% CI: 0.96, 1.04), 1.00 (95% CI: 0.96, 1.04), 0.98 (95% CI: 0.94, 1.02), and 0.99 (95% CI: 0.95, 1.04) respectively.
  
  
  CONCLUSIONS
  Risk of PROM was greater for pregnancies with elevated PM2.5 exposure in the second trimester than were other pregnancies to the same Australian women at lower exposure. There was insufficient evidence for an association with PTB, indicating that a longer time period might be needed to observe an association if a causal effect exists.
authors.affiliation: Telethon Kids Institute, The University of Western Australia, 100 Roberts Road, Subiaco, WA 6008, Australia; Center for Perinatal Pediatric and Environmental Epidemiology, School of Medicine, Yale University, New Haven, CT, United States. Electronic address: gavin.pereira@telethonkids.org.au.
authors.forename: Gavin
authors.initials: G
authors.lastname: Pereira
authors.affiliation: Center for Perinatal Pediatric and Environmental Epidemiology, School of Medicine, Yale University, New Haven, CT, United States; School of Forestry and Environmental Studies, Yale University, New Haven, CT, United States.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Bell
authors.affiliation: Center for Perinatal Pediatric and Environmental Epidemiology, School of Medicine, Yale University, New Haven, CT, United States.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Belanger
authors.affiliation: Telethon Kids Institute, The University of Western Australia, 100 Roberts Road, Subiaco, WA 6008, Australia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: de Klerk
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000633:toxicity*; D004781:Environmental Exposure; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000453:epidemiology*; D006801:Humans; D007231:Infant, Newborn; D008137:Longitudinal Studies; D052638:Particulate Matter / Q000633:toxicity*; D011247:Pregnancy; D011264:Pregnancy Trimesters; D047928:Premature Birth / Q000453:epidemiology*; D012306:Risk; D014904:Western Australia / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: Longitudinal study; Particulate matter; Pre-labor rupture of membranes; Pregnancy outcomes; Preterm birth