Background: Epidemiologic literature suggests that exposure to air pollutants is associated with fetal development.
Objectives: We investigated maternal exposures to air pollutants during weeks 2–8 of pregnancy and their associations with congenital heart defects.
Methods: Mothers from the National Birth Defects Prevention Study, a nine-state case–control study, were assigned 1-week and 7-week averages of daily maximum concentrations of carbon monoxide, nitrogen dioxide, ozone, and sulfur dioxide and 24-hr measurements of fine and coarse particulate matter using the closest air monitor within 50 km to their residence during early pregnancy. Depending on the pollutant, a maximum of 4,632 live-birth controls and 3,328 live-birth, fetal-death, or electively terminated cases had exposure data. Hierarchical regression models, adjusted for maternal demographics and tobacco and alcohol use, were constructed. Principal component analysis was used to assess these relationships in a multipollutant context.
Results: Positive associations were observed between exposure to nitrogen dioxide and coarctation of the aorta and pulmonary valve stenosis. Exposure to fine particulate matter was positively associated with hypoplastic left heart syndrome but inversely associated with atrial septal defects. Examining individual exposure-weeks suggested associations between pollutants and defects that were not observed using the 7-week average. Associations between left ventricular outflow tract obstructions and nitrogen dioxide and between hypoplastic left heart syndrome and particulate matter were supported by findings from the multipollutant analyses, although estimates were attenuated at the highest exposure levels.
Conclusions: Using daily maximum pollutant levels and exploring individual exposure-weeks revealed some positive associations between certain pollutants and defects and suggested potential windows of susceptibility during pregnancy.
1Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, North Carolina, USA; 2National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA; 3Department of Statistics, North Carolina State University, Raleigh, North Carolina, USA; 4Department of Pediatrics, and 5Department of Pediatrics Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; 6Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; 7Massachusetts Center for Birth Defects Research and Prevention, Massachusetts Department of Public Health, Boston, Massachusetts, USA; 8Department of Genetics and Pediatrics, University of Utah, Salt Lake City, Utah, USA; 9Department of Pediatrics, University of Mississippi Medical Center, Jackson, Mississippi, USA; 10National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, USA; 11Texas Center for Birth Defects Research and Prevention, Texas Department of State Health Services, Austin, Texas, USA; 12Arkansas Center for Birth Defects Research and Prevention, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; 13Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
Recommended Citation:
Jeanette A. Stingone,1 Thomas J. Luben,2 Julie L. Daniels,et al. Maternal Exposure to Criteria Air Pollutants and Congenital Heart Defects in Offspring: Results from the National Birth Defects Prevention Study[J]. Environmental Health Perspectives,2014-01-01,Volume 122(Issue 8):863