Total anomalous pulmonary venous return: familial and environmental factors. The Baltimore-Washington Infant Study Group.

In total anomalous pulmonary venous return (TAPVR), the intrapulmonary venous plexus has failed to connect to the left atrium, so that the pulmonary veins drain into right atrial tributaries, frequently resulting in early postnatal circulatory distress. The Baltimore-Washington Infant Study (BWIS), a population-based exploratory case-control study of cardiovascular malformations (CVM), identified 41 cases of TAPVR during 1981-1987: 1.5% of all CVM (N = 2659), a regional prevalence of 6.8/100,000 live births. Of the TAPVR infants, 68% were diagnosed as neonates, 88% had surgery, and 51.2% were alive at 1 year of age. Noncardiac malformations were present in nine cases (22%); the male-female ratio was 0.78 (18.23). Compared with a control group representative of the birth cohort (N = 2,801), more TAPVR patients had low birthweight (less than 2,500 g: 16.2% vs. 6.9%, short gestational age (less than 38 weeks: 18.9% vs. 9.3%), and intrauterine growth retardation (IUGR) (26.8% vs. 5.8%). Sociodemographic findings were similar to those of controls, except that fewer TAPVR mothers received private pregnancy care (59.5% vs. 71.4%). Family history revealed no other TAPVR-affected members, but a significant linear trend of increased risk was found over the ordered malformation categories (familial noncardiac, cardiac, both). Bivariate analysis of TAPVR and exposure in life-style, hobbies, and work showed possible associations for exposure to lead (OR 2.9; 99% confidence interval [CI]: 1.2, 7.2), painting/paint stripping (OR 3.3; 99% CI: 1.3, 8.4), lead soldering (OR 13.3; 99% CI: 1.8, 99.2), and pesticides (OR 2.7; 99% CI: 1.2, 6.4). Multivariate analysis suggested an interaction between pesticide exposure and family history and, thus, a possible familial susceptibility to environmental teratogens. Although the number of TAPVR cases is small, this epidemiologic study identifies hypotheses that may be further explored in morphogenetic and epidemiology studies. Total anomalous pulmonary venous return (TAPVR) constitutes a well-defined clinical entity in which the pulmonary veins fail to enter the left atrium and instead drain into the right atrium or its systemic venous tributaries (Neill, '56; Rowe et al., '81). During intrauterine life, the malformation does not compromise the fetal circulation, since the pulmonary arterial resistance is high and the patent foramen ovale provides easy access of right atrial blood to the left side of the heart. At birth, however, the pulmonary vascular resistance begins to fall, and the presence of a severe hemodynamic disturbance becomes increasingly evident (Ferencz et al., '71).(ABSTRACT TRUNCATED AT 400 WORDS)