| Approximately three percent of all children are born with a major birth defect, yet the cause of up to 70 percent of congenital malformations remains unknown. Previous epidemiologic studies have suggested that some paternal occupations may be associated with an increased risk of birth defects in offspring, so this relationship was evaluated using data from a population-based case-control study. Cases were infants with a major birth defect registered with the Metropolitan Atlanta Congenital Defects Program between 1968 and 1980. Controls were selected from livebirths in the Atlanta area and frequency matched to cases on race, year and hospital of birth. An interview was conducted with case and control parents soliciting information on a variety of factors, including occupation. Paternal occupational exposure was defined as the job held during the six months before to one month after conception. Because more mothers than fathers were located and interviewed, a concordance analysis was performed to assess the potential usefulness of the paternal occupation information obtained from mothers.; The exact agreement between mother's and father's report of paternal occupation was 59 percent. This was not deemed high enough for the mother's report to provide useful information, so the analyses of paternal occupation and birth defects were restricted to the 3,739 case and 2,279 control infants for whom both parents were interviewed.; The analysis of paternal occupation and birth defects in offspring failed to corroborate several associations found in previous studies such as painters and neural tube defects. Nonetheless, a number of associations were identified including: firemen with cleft lip (odds ratio (OR) = 13.3, 95 percent confidence interval (CI) = 4.0-44.4); painters with atrial septal defect (OR = 2.7, CI = 1.0-7.4); and farmers with cleft lip and palate (OR = 3.3, CI = 0.9-11.9). Several additional occupations were identified as potentially high risk for some defects, including printers, electronic equipment operators, and vehicle manufacturers. In order to evaluate the importance of these results, future studies should include a detailed exposure assessment component. |
