We sought to identify echocardiographic markers that might be useful for managing fetuses with significant aortic stenosis. The study was a retrospective review of fetal echocardiographic studies and postnatal outcomes of all fetuses diagnosed with significant aortic stenosis who did not have a hypoplastic left ventricle on the initial echocardiogram. Where possible, fetal echocardiographic measurements included the aortic, mitral, pulmonary, and tricuspid valve annulus sizes; left ventricular dimensions and volume; septal and left ventricular wall thicknesses; and echocardiographic Doppler interrogation of the left heart and oval fossa. Observations also included an assessment of ascites, pericardial effusion, and endocardial fibroelastosis. Prenatal measurements were compared to postnatal outcomes. Four patients (group 1) had either clinically successful relief of their aortic obstruction (n = 3) or required no intervention (n = 1). Five fetuses evolved to the hypoplastic left heart syndrome (group 2). These infants demonstrated little or no growth in left ventricular, aortic valve, or mitral valve dimensions on serial examination. They also more often exhibited mitral stenosis, severe restriction of interatrial shunting, and early to mid second trimester left ventricular dilatation. Serial measurements of fetal cardiac size and function are helpful for predicting the postnatal outcome of fetuses with aortic stenosis.

Objectives. Multiple technical difficulties are encountered when a multidisciplinary team of subspecialists begins a minimally-invasive fetal cardiac interventional program. We describe the learning curve. Study Design. Ten pregnant sheep underwent ultrasound-guided balloon valvuloplasty of the aortic valve. Team members and their roles remained constant through the trial. The time between needle insertion and entrance of the left ventricle at the aortic root was recorded. F-test was used to assess significance (P ≤ .05). Results. The time required to accurately position the needle tip at the aortic root decreased significantly over the course of the trial, from 12 minutes with the first attempt to one minute with the last (P = .003). Conclusion. A significant learning curve is encountered when a multidisciplinary team begins a minimally-invasive fetal cardiac intervention program. However, technical proficiency can be achieved with practice. Institutions interested in developing such a program should consider practice in an animal model before proceeding to the human fetus.