Paternal occupation and risk of birth defects in offspring

Several epidemiologic studies indicate that some paternal occupations are associated with an increased risk of birth defects in offspring. We evaluated this relation using data from a population-based case-control study. Cases are infants with a major birth defect registered with the Metropolitan Atlanta Congenital Defects Program between 1968 and 1980. We selected controls from livebirths in the Atlanta area using frequency matching for race, year, and hospital of birth. Case and control parents were interviewed to solicit information on several factors, including occupation. We classified paternal occupation according to the job held during the time from 6 months before until 1 month after the estimated date of conception. We compared fathers in one occupational category with fathers in all other categories combined. We identified a number of associations including: firemen with cleft lip [odds ratio (OR) = 13.3; 95% confidence interval (CI) = 4.0-44.4]; painters with atrial septal defect (OR = 2.7; 95% CI = 1.0-7.4); and farmers with cleft lip and palate (OR = 3.3; 95% CI = 0.9-11.9). This study, however, did not corroborate several associations found in previous studies, such as painters and neural tube defects. We identified several additional occupations as potential risk factors for some defects, including printers, electronic equipment operators, and vehicle manufacturers.