title: Associations between ambient air pollution and Hypertensive Disorders of Pregnancy.
abstract: BACKGROUND
  Exposure to ambient air pollution is linked to adverse pregnancy outcomes. Previous reports examining the relationship between ambient air pollution and Hypertensive Disorders of Pregnancy have been inconsistent.
  
  
  OBJECTIVE
  We evaluated the effects of ambient air pollution on the odds of Hypertensive Disorder of Pregnancy and whether these associations varied by body mass index (BMI).
  
  
  METHODS
  We conducted a retrospective, case-control study among 298 predominantly Hispanic women (136 clinically confirmed cases) who attended the Los Angeles County+University of Southern California Women's and Children's Hospital during 1996-2008. Trimester-specific carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and particulate matter with aerodynamic diameter <10 μm and <2.5 μm (PM10, PM2.5) exposure were estimated based on 24-hour exposure level at residential address. Logistic regression models were fitted to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for two standard deviation increase in exposure levels.
  
  
  RESULTS
  Exposures to CO and PM2.5 in the 1st trimester were significantly associated with Hypertensive Disorders of Pregnancy, and these associations were modified by BMI. In non-obese women (BMI <30), 1st trimester exposures to PM2.5 and CO were significantly associated with increased odds of Hypertensive Disorder of Pregnancy (ORs per 2-standard deviation increase in PM2.5 (7 μg/m(3)) and CO (1 ppm) exposures were 9.10 [95% CI: 3.33-24.6] and 4.96 [95% CI: 1.85-13.31], respectively). Additionally, there was a significantly positive association between exposure to O3 in the 2nd trimester and Hypertensive Disorder of Pregnancy (OR per 15 ppb=2.05; 95% CI: 1.22-3.46).
  
  
  CONCLUSIONS
  Among non-obese women, 1st trimester exposure to PM2.5 and carbon monoxide are associated with increased odds of Hypertensive Disorder of Pregnancy.
authors.affiliation: Department of Preventive Medicine, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Mobasher
authors.forename: Muhammad T
authors.initials: MT
authors.lastname: Salam
authors.forename: T Murphy
authors.initials: TM
authors.lastname: Goodwin
authors.forename: Frederick
authors.initials: F
authors.lastname: Lurmann
authors.forename: Sue A
authors.initials: SA
authors.lastname: Ingles
authors.forename: Melissa L
authors.initials: ML
authors.lastname: Wilson
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects* / Q000706:statistics & numerical data; D015992:Body Mass Index; D002248:Carbon Monoxide / Q000009:adverse effects; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000453:epidemiology / Q000209:etiology*; D015141:Los Angeles / Q000453:epidemiology; D009585:Nitrogen Dioxide / Q000009:adverse effects; D010126:Ozone / Q000009:adverse effects; D052638:Particulate Matter / Q000009:adverse effects; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012189:Retrospective Studies
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D010126:Ozone; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide