Association of Fetal Cerebrovascular Resistance and Neurodevelopment in Congenital Heart Disease: A Physiology‐Based Analysis

OBJECTIVE: To evaluate whether fetal cerebrovascular resistance estimated by middle cerebral artery pulsatility index (MCA PI) and cerebroplacental ratio (CPR) predicts 2-year neurodevelopment, accounting for physiology-based subtypes of congenital heart disease (CHD). METHODS: This cohort study included fetuses with isolated CHD and healthy controls. Cardiac physiology was classified by ventricular circulation, outflow obstruction and expected cerebral substrate concentration. All subjects underwent fetal echocardiography and neurodevelopmental evaluation at 2 years of age using the Bayley Scales of Infant and Toddler Development. RESULTS: There were no differences in MCA PI or CPR between cases (n = 74) and controls (n = 45). There were no associations between cerebral Dopplers and neurodevelopment in CHD overall. When stratified by fetal cardiac physiology, lower MCA PI was associated with higher Bayley cognitive, language, and motor scores and lower CPR with higher Bayley cognitive and language scores in cases with systemic outflow tract obstruction. Lower CPR was associated with higher cognitive score in single ventricle circulation. In multivariable analysis of predictors of neurodevelopment in cases overall, lower fetal brain volume predicted lower cognitive score, lower maternal education predicted lower language score, and lower fetal brain volume and single ventricle circulation predicted lower motor score. CONCLUSION: Lower cerebrovascular resistance predicted improved neurodevelopmental outcomes only among cases with systemic outflow tract obstruction and/or single ventricle physiology, suggesting that effective compensatory cerebral autoregulation is CHD-type specific.