Relationship between gestational age and outcomes after congenital heart surgery.

Abstract Background Previous studies suggest that birth prior to 39 weeks gestational age (GA) is associated with higher perioperative mortality and morbidity after congenital heart surgery. The optimal approach to timing of surgery in premature infants remains unclear. We investigated the impact of GA at birth and corrected GA at surgery on post-operative outcomes using the Pediatric Cardiac Critical Care Consortium (PC4) database. Methods Infants undergoing selected index cardiac operations before the end of the neonatal period were included (n=2,298). GA at birth and corrected GA at the time of index cardiac surgery were used as categorical predictors and fitted as a cubic spline to assess non-linear relationships. The primary outcome was hospital mortality. Multivariable logistic regression models assessed the association between predictors and outcomes while adjusting for confounders. Results Late-preterm birth (34-36 weeks) was associated with increased odds of mortality compared to full-term (39-40 weeks) birth while early-term birth (37-38 weeks) was not associated with increased mortality. Corrected GA at surgery of 34-37 weeks compared to 40-44 weeks was associated with increased mortality. When analyzing corrected GA at surgery as a continuous predictor of outcome, odds of survival improve as patients approach 39 weeks corrected GA. Conclusions Contrary to previous literature, we did not find an association between early-term birth and hospital mortality at PC4 hospitals. Our analysis of the relationship between corrected GA and mortality suggests that operating closer to full-term corrected GA may improve survival.