Abstract This is a report of the outcome of the pregnancy in 6 patients with intracardiac ball valve prostheses. Only 1 was not receiving anticoagulant agents, and she had a normal delivery with a live baby. The remaining 5 patients were receiving a coumarin anticoagulant agent throughout their pregnancies. Two patients had premature deliveries with live babies that died a few hours later. Three patients had stillbirths; in only 1 patient was an excessive anticoagulant effect observed during a week which coincided with the calculated date of fetal death. This was the only case in which the placenta was studied, disclosing scattered areas of infarction and hemorrhage. Autopsy of the fetus or infant was performed in 2 cases and multiple hemorrhages were found. The literature is reviewed and the probable relation between the use of coumarin anticoagulant agents and fetal and infant death is discussed. Recommendations are made for adequate control and management of pregnancy in women with an intracardiac prosthesis.