Cerebrovascular Blood Flow Dynamic Changes in Fetuses with Congenital Heart Disease

Abstract

Objective: The aim of this study was to determine whether the type of congenital heart disease (CHD) or heart function influence fetal cerebrovascular blood flow dynamics. Methods: Doppler flow velocimetry was performed in the umbilical artery (UA) and middle cerebral artery (MCA), and the ratio of the UA pulsatility index (PI) to the MCA PI (U/C PI) was determined in 45 fetuses with CHD at 20–40 weeks’ gestational age. The control group consisted of 275 healthy fetuses matched for gestational age. Individual PI measurements were converted into Z-scores for statistical analysis. Results: Fetuses with CHD (n = 45) had an increased UA PI (p = 0.001) and U/C PI (p < 0.001) when compared to controls. There was no significant difference in the MCA PI between fetuses with CHD (n = 45) and controls (n = 275), while fetuses with CHD complicated by congestive heart failure (CHF) (n = 10) had a decreased MCA PI (p < 0.001) compared to controls. Conclusions: The lower PIs observed in the MCA of fetuses with CHD complicated by CHF represents a marker of cerebral vasodilation that is due to cerebral hypoxemia and limiting perfusion. The heart function and type of CHD have an impact on fetal cerebrovascular blood flow distribution and this may contribute to the cause of abnormal neurologic development in these fetuses.

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

“…The results also confirm previous data suggesting impaired neurodevelopment in fetuses with CHD, including a significantly smaller head biometry at diagnosis [34] or in the third trimester [35,36], brain redistribution [16,17,34,35,37,38], smaller MRI TBrV and TICV [11,12] and a delay in cortical gyrification [12,13]. Finally, we found similar MRI spectroscopic results to those previously reported for neonates [10] and third-trimester fetuses [11] with CHD, showing decreased mean NAA/Cho ratios in several brain areas.…”

Impact of congenital heart disease on fetal brain development and injury

“…1a-f) [26]. Several studies have characterized cerebral resistance indices using Doppler ultrasound in human fetuses with CHD that are believed to be related to these alterations in flow created by the heart defect (Table 1) [27][28][29][30][31].…”

“…Abnormal cerebral pulsatility indices were found in 7% of fetuses with CHD, all with intracardiac mixing, versus none in the normal group. Guorong et al [30] evaluated 45 fetuses with CHD and compared findings with 275 controls. Fetuses with CHD had elevated umbilical to cerebral pulsatility indices ratios.…”

“…These brain findings may relate to injury after delivery, or to abnormal brain development or brain injury, caused by alterations in the in-utero circulation from the heart defect. In an autopsy study, Glauser et al [32] found that 45% of babies with HLHS, half of whom did not have surgery, had (SV À DV)/MV Lower value associated with higher mortality, growth retardation, and poor neurological outcome Lower in HLHS, and higher in right-sided obstruction lesions [27] Lower in TGA versus nl [28] Lower in CHD with intracardiac mixing [29] Lower in CHD fetuses with CHF [29] Cerebral resistance index (CRI) (SV À DV)/SV Lower value associated with growth retardation Lower in CHD infants versus nl [26] Cerebral/umbilical pulsatility ratio CPI/UPI Ratio <1 associated with growth retardation and poor outcome Increased in CHD [30] Cerebral/umbilical resistance ratio CRI/URI Ratio <1 associated with growth retardation and poor outcome…”

Changes in Fetal Circulation Associated with Congenital Heart Disease and Their Effects on Fetal Growth

“…Corresponding to previous reports, all fetuses with hypoplastic left-heart syndrome showed MCA RI ! 10th percentile [6,8,10,11] . Furthermore, most of the growth parameters during the fetal period and at birth were lower in the CHD group than in the control group.…”