Clinical Research Directory

Inclusion Criteria: Mothers carrying fetuses with small left sided structures likely needing neonatal intervention, defined as the following on fetal echocardiography: 1. Sum of aortic and mitral valve z-scores (standard deviation based on gestational age) less than -4.5 2. Flow across the atrial septum either bidirectional or left to right 3. Transverse aortic arch or isthmus z-score less than 2.0. Exclusion Criteria: 1. Severe fetal aortic stenosis 2. Fetal mitral or aortic atresia 3. Abnormal fetal atrioventricular or ventriculoarterial relationships, including double inlet left ventricle, double outlet right ventricle, transposition of the great arteries 4. Multiple gestations 5. Intrauterine growth restriction 6. Persistent fetal arrhythmia 7. Very poor ultrasound images, defined by the inability to reliably measure/evaluate all included cardiac structures 8. Major fetal extracardiac anomalies, specifically lesions that would be expected toi ncrease mortality for the fetus/neonate or would necessitate intervention in the neonatal period, including but not limited to congenital diaphragmatic hernia, omphalocele, gastroschesis, meningomyelocele, lower urinary tract obstruction, and anencephaly 9. Aneuploidy (although this is not required to be known to enroll 10. Maternal conditions that may alter fetal hemodynamic, including moderate to severe hypertension requiring medication in pregnancy, preeclampsia, major or unrepaired maternal congenital heart disease, obstructive sleep apnea, severe asthma (requiring daily treatment), restrictive lung disease, severe anemia (hemoglobin less than 8 g/dL), maternal chronic renal disease (creatinine greater than 1.2 mg/dL), known placental abnormality (complete placenta previa, accrete, or percreta), and antiphospholipid antibody syndrome.