Pregnancy and its complications following cardiac valve prostheses.

Approximately 100 cases of pregnancy in women with cardiac valve prostheses have been reported in the world's medical literature. In most instances, the need for continuous anticoagulation therapy constituted a major concern in the obstetric management of these high-risk pregnancies, particularly since coumarin has been implicated as causing an increased frequency of fetal wastage or birth defects (or both). Of all women who received cardiac valve prostheses at the Mayo Clinic between 1965 and 1975, 23 conceived 40 times after the procedure. Fetal wastage was more than doubled in women receiving coumarin therapy at conception and during the first trimester, as compared with that in women not receiving coumarin therapy. Fetal wastage exceeded 80% in women with multiple-valve prostheses who received coumarin therapy throughout early pregnancy. There were no serious maternal sequelae in any of the women. One infant of a mother receiving anticoagulation therapy had mild nasal hypoplasia, but there were no other congenital anomalies in which coumarin had been previously implicated.