title: Air pollution and stillbirth risk: exposure to airborne particulate matter during pregnancy is associated with fetal death.
abstract: OBJECTIVE
  To test the hypothesis that exposure to fine particulate air pollution (PM2.5) is associated with stillbirth.
  
  
  METHODS
  Geo-spatial population-based cohort study using Ohio birth records (2006-2010) and local measures of PM2.5, recorded by the EPA (2005-2010) via 57 monitoring stations across Ohio. Geographic coordinates of the mother's residence for each birth were linked to the nearest PM2.5 monitoring station and monthly exposure averages calculated. The association between stillbirth and increased PM2.5 levels was estimated, with adjustment for maternal age, race, education level, quantity of prenatal care, smoking, and season of conception.
  
  
  RESULTS
  There were 349,188 live births and 1,848 stillbirths of non-anomalous singletons (20-42 weeks) with residence ≤10 km of a monitor station in Ohio during the study period. The mean PM2.5 level in Ohio was 13.3 μg/m3 [±1.8 SD, IQR(Q1: 12.1, Q3: 14.4, IQR: 2.3)], higher than the current EPA standard of 12 μg/m3. High average PM2.5 exposure through pregnancy was not associated with a significant increase in stillbirth risk, adjOR 1.21(95% CI 0.96,1.53), nor was it increased with high exposure in the 1st or 2nd trimester. However, exposure to high levels of PM2.5 in the third trimester of pregnancy was associated with 42% increased stillbirth risk, adjOR 1.42(1.06,1.91).
  
  
  CONCLUSIONS
  Exposure to high levels of fine particulate air pollution in the third trimester of pregnancy is associated with increased stillbirth risk. Although the risk increase associated with high PM2.5 levels is modest, the potential impact on overall stillbirth rates could be robust as all pregnant women are potentially at risk.
authors: Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America; Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America.
authors: Emily
authors: E
authors: DeFranco
authors: Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America.
authors: Eric
authors: E
authors: Hall
authors: Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America.
authors: Monir
authors: M
authors: Hossain
authors: Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America.
authors: Aimin
authors: A
authors: Chen
authors: Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America.
authors: Erin N
authors: EN
authors: Haynes
authors: Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America.
authors: David
authors: D
authors: Jones
authors: Department of Mathematics, University of Cincinnati, Cincinnati, Ohio, United States of America; Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America.
authors: Sheng
authors: S
authors: Ren
authors: Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America.
authors: Long
authors: L
authors: Lu
authors: Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America; Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America.
authors: Louis
authors: L
authors: Muglia
mesh_terms: D000328:Adult; D000393:Air Pollutants; D000397:Air Pollution / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D052638:Particulate Matter / Q000009:adverse effects; D011247:Pregnancy; D012307:Risk Factors; D050497:Stillbirth / Q000453:epidemiology*
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter