Prenatal Maternal Hyperoxygenation Testing and Implications for Critical Care Delivery Planning among Fetuses with Congenital Heart Disease: Early Experience.

BACKGROUND:  Maternal hyperoxygenation (MH) during fetal ultrasound can characterize fetal pulmonary vasoreactivity (PVr) and its associations with postnatal physiology.

OBJECTIVE:  We explored MH testing to facilitate perinatal risk stratification for fetuses with congenital heart disease (CHD).

METHODS:  MH was performed in 12 fetuses: 2 with Ebstein anomaly, 2 with total anomalous pulmonary venous connection (TAPVC), 4 with hypoplastic left heart syndrome (HLHS) with (a) restrictive atrial septum (RAS) or (b) intact atrial septum (IAS) with decompressing vertical vein (VV), and 4 with D-loop transposition of the great arteries (TGA). PVr and physiologic and anatomic changes with MH and outcomes were recorded.

RESULTS:  Among Ebstein fetuses, pulmonary blood flow with MH mirrored postnatal findings. Among TAPVC fetuses, MH VV gradients correlated with postnatal gradients. One HLHS/IAS/VV fetus had no PVr and decreased pulmonary vein forward to reverse velocity time integral ratio with MH. Shortly after delivery, the infant experienced severe low cardiac output and required urgent atrial septoplasty. The remaining HLHS fetuses had PVr and underwent routine Stage 1 Norwood. Among TGA fetuses, septum primum position, foramen ovale flow, and the presence or absence of PVr with MH reflected postnatal findings.

CONCLUSION:  MH may help identify fetuses with CHD at risk for perinatal compromise. Additional study may yield insights into fetal PVr and elucidate predictors of perinatal outcomes.