County-level environmental quality and gastroschisis in the National Birth Defects Prevention Study
On this page:
The etiology of gastroschisis is not well understood. Genetic factors, young maternal age, low BMI, and isolated environmental exposures have been linked to gastroschisis, but the contribution of cumulative exposures across multiple socio-environmental domains has not been comprehensively examined. We used the Environmental Quality Index (EQI), a county-level estimate of cumulative exposures in five domains (air, water, land, sociodemographic, built) developed by the US Environmental Protection Agency (EPA), to assess the association between geographic environmental quality and gastroschisis in the National Birth Defects Prevention Study, a population-based case-control study of birth defects. This analysis included 594 gastroschisis cases and 4105 non-malformed controls born between 2006 and 2011 across 369 counties in 38 states from 9 centers. Logistic regression was used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) between gastroschisis and the EQI, represented by exposure tertiles (referent = T1 = “best” environmental quality) and adjusted for maternal age at conception (<20 or ≥20 years), race/ethnicity, periconceptional cigarette smoking, alcohol use, and maternal country of birth (US or non-US). For the EQI overall, the aORs for T2 and T3 were 1.11 (95% CI: 0.88, 1.40) and 1.02 (0.80, 1.29), respectively. Across the individual domains, comparing the worst environmental quality (T3) to the best (T1), the aORs were: air 1.04 (0.82, 1.33); water 1.31 (0.99, 1.73); land 0.99 (0.75, 1.30); sociodemographic 1.20 (0.86, 1.67); and built 1.28 (0.96, 1.70). While some individual socio-environmental factors have been associated with gastroschisis, we did not observe strong associations in this study with cumulative county-level exposures across multiple environmental domains. This abstract does not reflect EPA policy.