[Extracorporeal circulation in pregnancy: report of a case. Update and review of the literature].

Parameters of flow, temperature and perfusion, and modifications in body fluids secondary to surgery with extracorporeal circulation do not imply an increase in maternal risk during pregnancy but they eventually considerably increase fetal morbimortality. We present the case of a 22 week pregnant woman with severe aortic stenosis who underwent extracorporeal surgery for valve replacement without fetal mortality during the procedure. Literature about the use of extracorporeal surgery in the treatment of valve pathology in pregnancy, the parameters in which the reduction of fetal morbimortality is based and alternative treatments are broadly reviewed.