Patients with critical aortic valve or pulmonary valve stenosis may benefit from a fetal valvuloplasty. Our physicians have developed technology and techniques that maximize successful negotiation of the stenotic valve to improve the technical success rate and minimize the rate of complications. Fetal atrial septostomy for the treatment of fetuses with hypoplastic left heart syndrome and restrictive or intact interatrial septum is also offered. The procedures are done in the Hospital in the main Operating Room, under maximum antiseptic technique.