Oxygen boost for unborn babies with heart disease shows promise

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Pregnant mothers ≥18 years of age * Written maternal informed consent * Fetal diagnosis of one of the CHDs (1-3) as listed below and intention of active treatment after birth: 1. Single ventricular (SV) lesions: hypoplastic left heart syndrome (HLHS); pulmonary atresia with intact ventricular septum (PA/IVS); tricuspid atresia (TA); unbalanced AV septal defect (AVSD); double inlet ventricle (DILV); and severe form of Ebstein's anomaly (EA) of the tricuspid valve associated with functional or anatomical right outflow obstruction. HLHS will include aortic stenosis with mitral stenosis, aortic atresia with mitral stenosis or mitral atresia. Pulmonary or aortic obstruction is defined as a condition with minimal or absent antegrade flow across the respective valve. Severe forms of EA is defined as lesion without anterograde pulmonary flow in the setting of severe tricuspid regurgitation. 2. Bi-ventricular lesions with right ventricular outflow tract obstruction (BV/RVOTO); tetralogy of Fallot (TOF), TOF-like double outlet right ventricle (DORV), and pulmonary atresia with ventricular septal defect (PA/VSD). 3. Bi-ventricular lesions with transposed great arteries (TGA w/ VSD; TGA w/o VSD; DORV with TGA) Exclusion Criteria: * Termination of pregnancy * Unusual CHDs (e.g. EA with circular shunt, TOF with AVSD, and TOF with absent pulmonary valve syndrome, TGA associated with moderate- severe outflow tract obstruction * Complex cardiac condition (e.g poor fetal cardiac function and/or fetal hydrops, fetal arrhythmia such as frequent premature atrial beats, abnormal baseline heart rate (\<110 bpm; \> 160 bpm) in the third trimester) * Major non-cardiac lesions and major genetic abnormalities affecting brain size and development * Significant maternal co-morbidities that precludes a fetal MRI (e.g. significant obesity, claustrophobia) * Multiple pregnancy