In the uncommon patient who develops severe symptoms despite medical management, intervention on the mitral valve is required. Percutaneous mitral balloon valvotomy now can be performed with a high success rate in pregnant patients, if there is a favorable valve morphology. However, it must be emphasized that the majority of patients will be able to be carried through pregnancy without the need for any intervention. There is no ideal prosthetic valve for the pregnant patient. Bioprostheses do not require anticoagulation but undergo accelerated deterioration during pregnancy and the patient must be prepared to undergo a second surgery within years.
Mechanical prostheses are more durable but have the attendant risks of anticoagulation.
The management of anticoagulation in the pregnant patient is highly controversial. Conventional wisdom has cautioned against the use of Coumadin throughout the pregnancy. Coumadin crosses the placenta and has a higher level in the fetus than the mother due to the developing liver enzymatic process. There is a known risk of fetal damage and embryopathy if Coumadin is used in the first trimester. There is a risk of fetal hemorrhage during delivery if Coumadin is still present.