White-black differences in cardiovascular malformations in infancy and socioeconomic factors. The Baltimore-Washington Infant Study Group.

Cardiovascular malformations were examined for white/black variation in the Baltimore-Washington Infant Study. In this population-based case-control study, cases (n = 2,087) were live births with cardiovascular malformations ascertained through pediatric cardiology centers and 53 hospitals in Maryland, the District of Columbia, and northern Virginia between 1981 and 1987. Controls (n = 2,721) were a random sample of infants from the live-birth cohort that gave rise to the cases. The proportion of infants that were white was similar for all cases as a group and controls (0.68 and 0.67, respectively). Subgroup analysis, however, revealed an excess of white infants among cases with Ebstein's anomaly (odds ratio (OR) = 3.7, 95% confidence interval (Cl) 1.1-12.5), aortic stenosis (OR = 3.6, 95% Cl 1.7-7.6), pulmonary atresia (OR = 2.5, 95% Cl 1.0-6.1), coarctation of the aorta (OR = 2.2, 95% Cl 1.4-3.5), and D-transposition of the great arteries (OR = 1.6, 95% Cl 1.1-2.5), and a deficit of white infants among cases with pulmonary stenosis (OR = 0.6, 95% Cl 0.4-0.8) and heterotaxia (OR = 0.4, 95% Cl 0.3-0.8). These associations remained when cases were stratified by infant's age or by method of diagnosis. Controlling for socioeconomic factors attenuated the white excess for Ebstein's anomaly (OR = 3.0, 95% Cl 0.9-10.5), disclosed a white excess among cases of L-transposition of the great arteries (OR = 2.8, 95% Cl 1.0-8.0), and revealed that the white excess for aortic stenosis was limited to low and middle socioeconomic strata. These results highlight racial variations in cardiovascular malformations, suggest that socioeconomic factors account for some of this variation, and identify malformation subgroups for which further evaluation of sociocultural, environmental, and familial factors is needed.