Advances in fetal cardiac intervention.

Fetal cardiac intervention is in a rapid state of progress now. Attempts are being made to prevent fetal hydrops due to congenital heart defects, to recruit hypoplastic ventricles, to create a two-ventricle circulation after birth, and to remodel the fetal pulmonary vascular bed whose outlet is obstructed. Open heart surgery in the fetus has yet to be done successfully, but interventions for improved cardiac outcomes are now being tested. Their outcomes will depend, in large part, on their successful physiological effects. How to measure these and quantitate the effects of our interventions will require further advances in the understanding of these diseases-both their natural and unnatural courses. New ultrasound techniques and assessment tools to assess fetal cardiac wellness could enhance the limited progress in fetal intervention in the heart so far.