Assessment of the association between congenital heart defects and brain injury in fetuses through magnetic resonance imaging

Background: Congenital heart defects (CHD) may be associated with neurodevelopmental abnormalities mainly due to brain hypoperfusion. This defect is attributed to the major cardiac operations these children underwent, but also to hemodynamic instability during fetal life. Advances in imaging techniques have identified changes in brain magnetic resonance imaging (MRI) in children with CHD. Objectives: To examine the correlation between CHD and brain injury using fetal brain MRI. Methods: We evaluated 46 fetuses diagnosed with CHD who underwent brain MRI. CHD was classified according to in situs anomalies, 4 chamber view (4CV), outflow tracts, arches, and veins as well as cyanotic or complex CHD. We compared MRI results of different classes of CHD and CHD fetuses to a control group of 113 healthy brain MRI examinations. Results: No significant differences were found in brain pathologies among different classifications of CHD. The anteroposterior percentile of the vermis was significantly smaller in fetuses with abnormal 4CV. A significantly higher biparietal diameter was found in fetuses with abnormal arches. A significantly smaller transcerebellar diameter was found in fetuses with abnormal veins. Compared to the control group, significant differences were found in overall brain pathology in cortex abnormalities and in extra axial findings in the study group. Significantly higher rates of overall brain pathologies, ventricle pathologies, cortex pathologies, and biometrical parameters were found in the cyanotic group compared to the complex group and to the control group. Conclusions: Fetuses with CHD demonstrate findings in brain MRI that suggest an in utero pathogenesis of the neurological and cognitive anomalies found during child development.