Mechanical prosthetic mitral valve thrombosis in a first trimester pregnant woman.

Pregnant women with a mechanical heart prosthesis are at a higher risk of thromboembolic complications. The optimal anticoagulation strategy in this setting remains unclear. When prosthesis thrombosis happens and cardiac surgery must be performed, the risk of fetal mortality is high. Special attention must be paid to improve the placental perfusion during cardiopulmonary bypass (CPB) in order to improve fetal outcomes. A 31-year-old woman, nine weeks pregnant, was admitted to our institution due to a mitral mechanical prosthesis thrombosis. She had been receiving low molecular weight heparin (LMWH) since pregnancy was detected. She underwent a mitral valve replacement with CPB at 34 degrees C and a short cardiac arrest time. Both mother and fetus survived. We briefly review the different anticoagulation options during pregnancy and perfusion strategies on CPB to improve fetal outcomes.