MATERNAL SOCIO-ENVIRONMENTAL EXPOSURES DURING EARLY PREGNANCY AND MORTALITY AMONG CHILDREN BORN WITH CRITICAL CONGENITAL HEART DEFECTS

Background: Children with critical congenital heart defects (CCHDs) experience high infant mortality (~25%). While various factors like severity and prenatal diagnosis impact survival, the role of environmental exposures remain understudied. We evaluated the associations between maternal neighborhood-level socioeconomic position (nSEP) and air pollution exposure during early pregnancy and survival in children with CCHDs. Methods: Children with CCHDs in the National Birth Defects Prevention Study (1999–2011) classified as univentricular (UVHDs; more severe) or biventricular (BVHDs) were linked to vital records for 1-year and 5-year mortality. To characterize nSEP, we applied principal component analysis to construct the Neighborhood Deprivation Index (NDI) [low (reference), moderate, or high deprivation] based on maternal addresses reported via interview. To evaluate per-IQR increases in ambient air pollutants, we assigned weekly averages (gestational weeks 2-8) using the nearest air monitor ≤50 kilometers. We estimated survival probabilities and hazard ratios (HRs) with 95% confidence intervals (CIs), adjusting for maternal and infant characteristics. Results: One-year survival was high (87-92%), though lower among children with UVHDs (60-75%) than BVHDs (93-95%). Among all CCHDs, survival differed significantly by deprivation (p