Congenital heart disease confers gestational age-dependent risks of mortality and morbidity in preterm infants.

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.