title: Acute and recent air pollution exposure and cardiovascular events at labour and delivery.
abstract: OBJECTIVE
  To study the relationship between acute air pollution exposure and cardiovascular events during labour/delivery.
  
  
  METHODS
  The Consortium on Safe Labor (2002-2008), an observational US cohort with 223,502 singleton deliveries provided electronic medical records. Air pollution exposure was estimated by modified Community Multiscale Air Quality models. Cardiovascular events (cardiac failure/arrest, stroke, myocardial infarcts and other events) were recorded in the hospital discharge records for 687 pregnancies (0.3%). Logistic regression with generalised estimating equations estimated the relationship between cardiovascular events and daily air pollutant levels for delivery day and the 7 days preceding delivery.
  
  
  RESULTS
  Increased odds of cardiovascular events were observed for each IQR increase in exposure to nitric oxides at 5 and 6 days prior to delivery (OR=1.17, 99% CI 1.04 to 1.30 and OR=1.15, 1.03 to 1.28, respectively). High exposure to toxic air pollution species such as ethylbenzene (OR=1.50, 1.08 to 2.09), m-xylene (OR=1.54, 1.11 to 2.13), o-xylene (OR=1.51, 1.09 to 2.09), p-xylene (OR=1.43, 1.03 to 1.99) and toluene (OR=1.42, 1.02 to 1.97) at 5 days prior to delivery were also associated with cardiovascular events. Decreased odds of events were observed with exposure to ozone.
  
  
  CONCLUSIONS
  Air pollution in the days prior to delivery, especially nitrogen oxides and some toxic air pollution species, was associated with increased risk of cardiovascular events during the labour/delivery admission.
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland, USA Northern Finland Laboratory Centre NordLab, Oulu, Finland Department of Clinical Chemistry, University of Oulu, Oulu, Finland Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland Department of Chronic Disease Prevention, National Institute for Health and Welfare, Oulu, Finland.
authors.forename: Tuija
authors.initials: T
authors.lastname: Männistö
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland, USA.
authors.forename: Pauline
authors.initials: P
authors.lastname: Mendola
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Laughon Grantz
authors.affiliation: Glotech Inc., Rockville, Maryland, USA US Food and Drug Administration, Silver Spring, Maryland, USA.
authors.forename: Kira
authors.initials: K
authors.lastname: Leishear
authors.affiliation: Biostatistics and Bioinformatics Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland, USA.
authors.forename: Rajeshwari
authors.initials: R
authors.lastname: Sundaram
authors.affiliation: The EMMES Corporation, Rockville, Maryland, USA.
authors.forename: Seth
authors.initials: S
authors.lastname: Sherman
authors.affiliation: Zachry Department of Civil Engineering, Texas A&M University, College Station, Texas, USA.
authors.forename: Qi
authors.initials: Q
authors.lastname: Ying
authors.affiliation: Biostatistics and Bioinformatics Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland, USA.
authors.forename: Danping
authors.initials: D
authors.lastname: Liu
mesh_terms: D000328:Adult; D000397:Air Pollution / Q000009:adverse effects / Q000032:analysis; D036861:Delivery, Obstetric / Q000379:methods / Q000401:mortality; D057286:Electronic Health Records; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D009589:Nitrogen Oxides / Q000032:analysis / Q000633:toxicity; D017063:Outcome Assessment, Health Care; D010126:Ozone / Q000032:analysis / Q000633:toxicity; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000139:chemically induced / Q000453:epidemiology / Q000517:prevention & control; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D014992:Xylenes / Q000032:analysis / Q000633:toxicity
chemical_list: D009589:Nitrogen Oxides; D014992:Xylenes; D010126:Ozone