Most patients with mild to moderate AS can tol- erate the hemodynamic changes of pregnancy without cardiovascular events. Patients with severe AS are at an increased risk of complica- tions, with HF developing in 10% to 44% of patients and arrhythmias in up to 25%, even if they were asymptomatic before pregnancy. Progressive as well as sudden deterioration may occur during pregnancy and delivery in patients with severe AS. Fetal complications are frequent also. Options for relief of valvular AS in young women include percutaneous aortic balloon dilation in patients with noncalcified congeni- tal AS, the Ross procedure, or a surgical bio- prosthetic or mechanical valve. TAVI has not been studied in young women, and few data Recommendations for Pre-Pregnancy Intervention in Women With VHD (Continued) COR LOE Recommendations CLINICAL STATEMENTS AND GUIDELINES exist on outcomes with this valve type during 6. Some women with severe asymptomatic AS, normal LV systolic function, and normal bio- markers may choose to undergo pregnancy without valve intervention. The risks of dete- rioration during pregnancy must be balanced against the risk of mechanical valve complica- tions during pregnancy or the long-term risks of a bioprosthetic valve in a young patient. In experienced centers, these women can often be treated with activity restriction, volume management, and optimization of loading 7. The threshold for valve operation for valve regurgitation is higher in the asymptomatic patient who might ever become pregnant than in patients who will not become pregnant because there always is the possibility that valve repair will not be successful and a prosthetic valve will be needed. Most patients with asymp- tomatic severe MR tolerate the hemodynamic changes of pregnancy, and there is no evidence for acceleration of LV dysfunction during preg- nancy. 