Abstract
OBJECTIVE: To determine the incremental risks of mortality and major neonatal morbidities associated with congenital heart disease (CHD) beyond prematurity alone.
STUDY DESIGN: Secondary analysis of two North American neonatal registries (2010-2022) including infants <35 weeks' gestation: 11,221 with CHD from the Children's Hospitals Neonatal Consortium and 720,846 without CHD from the Vermont Oxford Network. The primary outcome was in-hospital mortality. Secondary outcomes were major neonatal morbidities.
RESULTS: Preterm infants with CHD had fourfold higher odds of in-hospital mortality (OR 4.0, 95% CI 3.76-4.21). Mortality was similar at ≤26 weeks' gestation, but the relative impact of CHD increased with advancing gestational age. CHD was associated with significantly increased risks of severe bronchopulmonary dysplasia, intraventricular hemorrhage, and necrotizing enterocolitis.
CONCLUSION: The impact of CHD on mortality is gestational age dependent, with prematurity predominating at the lowest gestational ages and CHD increasingly driving mortality as gestational maturity improves.