A case-control study of parental occupational lead exposure and total anomalous pulmonary venous return

Total anomalous pulmonary venous return (TAPVR) is a rare cardiovascular malformation that occurs when the pulmonary vein connects to the right atrium or its tributaries causing infants to receive insufficient oxygenated blood. Few studies have investigated the etiology of TAPVR; however, within the Baltimore-Washington Infant Study (BWIS), a large case-control study of cardiovascular malformations, TAPVR was significantly associated with maternal exposure to soldering with lead and painting and paint stripping. However, these results were based on self-reported exposures which tend to underestimate exposures and are susceptible to recall bias. Furthermore, the role of paternal exposures was not evaluated.; In order to examine this association further, a case-control study of parental occupational lead exposure and TAPVR was designed within the BWIS. Cases included 54 live-born infants with TAPVR and controls were a stratified random sample of 522 live-born infants from the BWIS control group. Occupational lead exposure was assessed by industrial hygienists (IH) and a job exposure matrix using occupational histories collected during the BWIS interview. Furthermore, self-reported occupational and non-occupational exposures were reviewed.; The prevalence of maternal occupational lead exposure as assessed by IH was very low and not associated with TAPVR. Paternal occupational lead exposure was associated with a non-significant, 50% increased odds of TAPVR after adjusting for maternal residence at delivery, maternal pesticide exposure during the critical period, maternal employment during the critical period, and infant race; however, this association decreased when using a combined exposure measure from three hygienists that was calibrated for the probability of direct exposure and the IH's knowledge of the job (odds ratio (OR) = 1.29; 95% confidence interval (CI): 0.69–2.61). When both occupational and non-occupational lead exposures were combined, maternal lead exposure was associated with a 50% increased odds of TAPVR (OR = 1.57; 95% CI: 0.64–3.47) and paternal exposure was associated with an 80% increased odds (OR = 1.79; 95% CI: 0.99–3.23). When both parents were exposed there was a significant three-fold increased odds of TAPVR (OR = 2.94; 95% CI: 1.03–7.60). This study suggests a potential association between parental lead exposure and TAPVR. Further studies are needed to corroborate this association and elucidate the possible biological mechanism.