Congenital heart disease (CHD) is an attractive target for fetal therapy. With the development of successful neonatal repair for many types of CHD over the last 20 years, fetal therapy has become the next frontier. Concurrent advances in interventional catheterization and fetal imaging provided a foundation for the novel field of fetal cardiac intervention. This article focuses on the current status of in utero catheter interventions for CHD with particular interest in therapy for defects characterized by progressive stenosis or atresia of the semilunar valves, the aortic and pulmonary, with development of subsequent ventricular hypoplasia.