Introduction: In a pilot study of chronic maternal hyperoxygenation (CMH) in left heart hypoplasia (LHH), we sought to determine effect estimates of CMH on head size, vascular resistance indices, and neurodevelopment compared to controls.
Material And Methods: Nine gravidae meeting the inclusion criteria (fetal LHH, ≥25.9 weeks' gestation, and ≥10% increase in percent aortic flow after acute hyperoxygenation) were prospectively enrolled.