Severity of Fetal Brain Abnormalities in Congenital Heart Disease in Relation to the Main Expected Pattern of in utero Brain Blood Supply.

Objectives: We evaluated the hypothesis that in fetuses with congenital heart disease (CHD) there is a correlation between the expected pattern of in utero brain blood supply and the severity of neurodevelopmental impairment.

Methods: A total of 58 fetuses with CHD and 58 controls underwent a Doppler ultrasound and fetal MRI at 36-38 weeks. Fetuses with CHD were divided into two functional classes: class A with an expected severe reduction in oxygenated brain blood supply (left outflow tract obstruction and transposition of great vessels) and class B with theoretically near-normal or mildly impaired oxygenated brain blood supply (other CHD). Head biometry and cerebroplacental Doppler were assessed by ultrasound, and brain volumetry, cortical development and metabolism by MRI.

Results: Both class A and B CHD fetuses had significant differences in head biometry, brain perfusion, cortical development and brain metabolism compared with controls. However, there was a significant linear tendency for head biometry, cerebral Doppler, volumes, cortical sulcation and metabolic ratios across the three clinical groups, with signs of more severe brain alterations in type A CHD fetuses.

Conclusions: All fetuses with CHD showed significant brain developmental changes, but differences were more pronounced in CHD associated with an expected severe reduction in oxygenated blood supply to the brain.