The type of intervention will be dependent on the valve morphology and on the expertise of the center. The intervention should always be performed in a center with a multidis- ciplinary group of cardiologists, interventionalists, cardiac anesthesiologists, and obstetricians spe- cializing in high-risk obstetrics.1 7,9 12 2. Patients with severe rheumatic MS may develop progressive HF or sudden hemodynamic deteriora- tion during the hemodynamic stress of pregnancy. Percutaneous balloon dilation of the mitral valve is a high-risk procedure during pregnancy for both the mother and the fetus and should be performed only if there is hemodynamic deterioration or if there are severe NYHA class III or IV HF symptoms.17 19 The intervention will also be dependent on an accept- able valve morphology. The intervention should always be performed in a center with a multidisci- plinary group of cardiologists, interventionalists, car- diac anesthesiologists, and obstetricians specializing in high-risk obstetrics.1 7,9 12,20 3. Regurgitant valve lesions are generally better toler- ated during pregnancy than are stenotic ones. Valve surgeryisreasonableonlyintherarepregnantwoman with severe valve regurgitation with NYHA class IV HF symptoms refractory to medical therapy.13 16 4. Valve surgery during pregnancy is high risk, with a 30% to 40% fetal mortality rate and up to 9% maternal mortality rate reported. It should be reserved only for patients with severe, intractable symptoms unresponsive to bed rest and maxi- mally tolerated medical therapy.13 16 13.2. Prosthetic Valves in Pregnant Women 13.2.1. Initial Management Recommendations for Initial Management of Prosthetic Heart Valves in Pregnant Women Referenced studies that support the recommendations are summarized in Online Data Supplement 44. COR LOE Recommendations Women with a prosthetic valve should undergo pre-pregnancy assessment, including echocardiography, by a cardiologist with expertise in managing women with VHD during pregnancy. 