ObjectivesThe study objectives were to compare the neurodevelopmental outcomes of preschool survivors of the Fontan procedure with those of children with congenital heart disease undergoing biventricular repair and to investigate predictors of neurodevelopmental outcome for those with single ventricle congenital heart disease, including hypoplastic left heart syndrome. MethodsNeurodevelopmental outcomes were assessed at 4 years of age, including cognition, visual–motor integration, behavior, social skills, and academic achievement. Unadjusted outcomes were compared between patients with biventricular circulation and patients with single ventricles. Predictors of neurodevelopmental outcome were assessed in the patients with single ventricles. Multiple covariate models were evaluated using patient-related, operative, and postoperative covariates. ResultsNeurodevelopmental evaluation was performed in 365 children, 112 after the Fontan procedure (hypoplastic left heart syndrome, n = 91; other single ventricle, n = 21) and 253 after biventricular repair. Compared with patients with biventricular circulation, patients with single ventricles performed worse in terms of processing speed, inattention, and impulsivity. Otherwise, there were no significant differences between the groups for any domain. There was a trend toward lower performance for patients with single ventricles on visual motor integration. Outcomes for patients with hypoplastic left heart syndrome were not worse than for other forms of functional single ventricle. Patient factors were more important predictors of neurodevelopmental outcomes than were operative management variables. ConclusionsIn this cohort, unadjusted neurodevelopmental outcomes for preschool survivors of the Fontan procedure are similar to those for children with congenital heart disease undergoing biventricular repair for most domains. Among the patients undergoing the Fontan procedure, hypoplastic left heart syndrome was not associated with worse outcomes compared with other forms of single ventricle.