“…The evolution of more severe secondary pathology, including a hypoplastic left or right ventricle in the presence of severe semilunar valve obstruction and restriction of the foramen ovale, has prompted the development of invasive procedures to ameliorate the obstruction prenatally. To date, balloon aortic and pulmonary valvuloplasty [59][60][61] and atrial septoplasty and stent placement have been described, with moderate success [62].…”