Twenty-five women with prosthetic heart valves (PHV) became pregnant 28 times. Twenty-six of the pregnancies occurred while the patients were receiving oral anticoagulants and these were continued throughout in 25 pregnancies. Dipyridamole or dipyridamole and acetylsalicylic acid were used in 22 pregnancies. Eighteen infants were delivered, one with a congenital corneal leukoma; none had hemorrhagic complications; their psychomotor development was normal. Nine women aborted 10 times, including patients with two PHV, pelvic trauma and self-induced abortion. We could not detect excess anticoagulation in eight of the nine who had spontaneous losses; excess anticoagulation occurred five weeks before an abortion. There were no maternal deaths despite numerous complications; in two women, brain embolism was related to short interruptions of anticoagulation. The details of management are mentioned. We lack enough evidence to suggest routine sterilization, routine interruption of coumarin therapy during pregnancy or routine interruption of pregnancy in women with certain types and models of PHV; however, pregnancy under such conditions, plus antithrombotic therapy, carries a high risk for the product and a potential teratogenic effect. Women with one or two PHV can have children if their management is closely supervised and if extreme care is taken with the use of oral anticoagulants.