OP13.01: Cerebral blood flow redistribution in fetuses with congenital heart disease

Abstract

Congenital heart disease (CHD) is known to be associated to and increased risk of abnormal neurodevelopmental outcome, even in the absence of surgical intervention. Recent studies have established a strong link between fetal arterial redistribution and poorer neurodevelopmental outcome after birth. The aim of this study was to explore cerebral blood flow perfusion in fetuses with CHD during the third trimester of pregnancy. Retrospective case series of fetuses with a diagnosis of major CHD. Fetuses affected by placental insufficiency were excluded. Middle cerebral artery (MCA) and cerebro-placental ratio (CPR), expressed as the ratio between MCA and umbilical artery (UA) PI, were analysed in patients with CHD from 28 weeks of gestation. The proportion of fetuses with abnormal MCA PI or CPR, defined as below the 5th centile for a given gestational age, was calculated and the distribution of abnormal Doppler finding among different types of CHD was analysed using Chi-square test for trend. 132 normally grown fetuses with CHD were included in the analysis. The proportion of fetuses with abnormal Doppler findings, expressed MCA or CPR <5th centile, was 62.41% (95% confidence intervals, C.I. 53.9%-70.2%). Signs of brain redistribution were present in 46.15% (95% C.I. 23.2%-70.1%) of fetuses with AVSD, 61.54% (95% C.I. 45.7%-75.1%) in cases with VSD, in 66.67% (95% C.I. 46.2-82.2) of the cases of cono-truncal abnormalities, 72.41% (95% C.I. 54.1-85.5) of cases with obstruction of the right or left outflow tracts and in 30.00% (95% C.I. 10.3-70.8) in fetuses with transposition of the great arteries with a significant statistical difference among the different categories of CHD (p = 0.0002). Normally grown fetuses with CHD have a higher than expected rate of redistribution of cerebral blood flow in the absence of placental insufficiency. This finding suggests a possible pathophysiological mechanism for the high rate of neurodevelopmental outcome observed in these patients.