Brain Injury and Dysmaturation in Newborns with Congenital Heart Disease Born Preterm. Abstract: Preterm birth and congenital heart disease (CHD) are two of the most common sources of perinatal morbidity in high resource countries. Both conditions are associated with acquired brain injury and adverse neurodevelopmental outcomes. Very little is known about the combined risk for newborns with congenital heart disease that are born preterm and how this risk is affected by variable approaches to palliative or definitive surgical strategies to repair heart defects. In addition to brain injury, an increasing number of genetic anomalies have been identified in CHD that may contribute to ND outcomes. Our extensive experience imaging term babies with CHD and preterm babies without CHD, combined with high and increasing volume of this vulnerable population at our two centers uniquely positions us to describe the risk and magnitude of acquired brain injury as well as comparative brain development in CHD newborns born preterm with respect to intervention strategies. Our long-term goal is to optimize neurodevelopmental outcomes. In this proposal, we will leverage cross-center practice variability in timing and choice of surgical interventions, palliative versus definitive, to determine the association of surgical intervention strategy with brain development and risk of brain injury. We will also perform a comprehensive genetic evaluation to determine how genetic anomalies alter susceptibility to brain injury and ND outcome.