A pregnant woman with a prosthetic mechanical valve.

A 24-year-old woman who was 11 weeks pregnant and had a mechanical mitral valve presented at the emergency department with ischemic stroke. Although treatment with aspirin and unfractionated heparin was initially successful, subsequent management was almost impossible, as she eventually suffered a right hemispheric stroke, requiring percutaneous intervention and an emergency cesarian; prosthetic valve thrombosis with hemodynamic instability; and multiple bleeding complications. This case demonstrates how difficult it can be to select the appropriate treatment strategy for prosthetic valve thrombosis.