Heart surgery with cardiopulmonary bypass in pregnant women.

OBJECTIVE Definite data in heart surgery with extracorporeal circulation during pregnancy is limited. This report analyzes our experience in this area. METHODS Fifteen women underwent open heart surgery under cardiopulmonary bypass during pregnancy at our institution between 1972 and 1998. Surgical procedures included valve replacement in 13 patients (12 mitral, 1 aortic), declotting of a tilting disk mitral prosthesis in one and closure, of an atrial septal defect in the remaining patient. RESULTS Thirteen patients were in New York Heart Association functional class III to IV and were operated on urgently. Eight of these women had severe acute dysfunction of either a mechanical or a biological mitral prosthesis. There were 2 maternal operative deaths for a rate of 13.3%. Fetal losses resulted at the time of these maternal deaths. Fetal deaths occurred in 5 of the 13 pregnancies (38.5%) in women who survived the surgical procedure. CONCLUSIONS Because of the fetal risks, open heart surgery during pregnancy should be advised only in extreme emergencies. Although pregnancy per se does not increase the maternal risk, a high maternal mortality results from the emergency nature of the surgical intervention. Fetal mortality remains high.