title: Geographic and occupational risk factors for ventricular septal defects: Washington State, 1987-2003.
abstract: OBJECTIVE
  Ventricular septal defect (VSD) is currently the most common congenital cardiac malformation in the United States, but little is known about its etiology. The objective of this study was to address the hypothesis that parents' residence in eastern Washington, a region heavily dominated by the agricultural industry, and employment in agriculturally related occupations can influence the presence of a VSD in their offspring.
  
  
  METHODS
  Population-based case-control study.
  
  
  METHODS
  Washington State from January 1, 1987, through December 31, 2003.
  
  
  METHODS
  Children aged 0 to 2 years diagnosed as having a VSD (n = 3489), and other infants selected at random as control subjects (n = 13 290).
  
  
  METHODS
  Parental occupation and county of maternal residence were obtained from the birth certificate. The latter was categorized according to region (east vs west), rural-urban classification, and the proportion of farm and crop land.
  
  
  METHODS
  Diagnosis of VSD within the first 2 years of life.
  
  
  RESULTS
  The risk of VSD was greater for infants whose mothers resided in eastern Washington (odds ratio, 1.30; 95% confidence interval, 1.03-1.65). The risk of VSD with other cardiac malformations (n = 1205) exhibited a stronger geographic association than did isolated VSD (n = 2284). Analyses restricted to eastern Washington did not reveal a clear relationship between the risk of VSD and an increasing proportion of agricultural land in the mother's county of residence. Parental occupation in agriculture was not associated with the presence of VSD.
  
  
  CONCLUSIONS
  Although these findings suggest regional variation in Washington State in the occurrence of VSD, the basis for this variation remains to be determined.
authors.affiliation: Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA.
authors.forename: Maneesh
authors.initials: M
authors.lastname: Batra
authors.forename: Carrie L
authors.initials: CL
authors.lastname: Heike
authors.forename: Richard C
authors.initials: RC
authors.lastname: Phillips
authors.forename: Noel S
authors.initials: NS
authors.lastname: Weiss
mesh_terms: D000328:Adult; D002675:Child, Preschool; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006345:Heart Septal Defects, Ventricular / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects*; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D014861:Washington / Q000453:epidemiology