Fetal Cerebrovascular Autoregulation in Congenital Heart Disease and Association With Neonatal Neurobehavior

"* Phase 1- Baseline: A fetal echocardiogram will be performed as part of routine standard clinical care.~* Phase 2- MH: The participant will be placed on 8 litres of 100% FiO2 (inspired oxygen fraction) via a non-rebreather face mask for 10 minutes. After 10 minutes, additional images will be obtained. MH will be discontinued after additional imaging is complete.~* Phase 3- Recovery: After at least 5 minutes of discontinuation of MH, additional images will be obtained to ensure any changes have returned back to baseline."

Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS) evaluation: All neonates with CHD expected to undergo neonatal cardiac intervention or surgery have pre-operative NNNS assessment as PCH as standard of care. The NNNS takes approximately 30 minutes to complete. It is administered by a licensed physical, speech, or occupational therapist who has completed training and additional certification. The NNNS therapist will be blinded to the results of the fetal echocardiogram and MCA-PI.