Mesenteric vein thrombosis following impregnation via in vitro fertilization-embryo transfer.

Pregnancy is an acquired hypercoagulable state. Most patients with thrombosis that develops during pregnancy present with deep vein leg thrombosis and/or pulmonary embolism, whereas the development of mesenteric vein thrombosis (MVT) in pregnant patients is rare. We report a case of MVT in a 34-year-old woman who had achieved pregnancy via in vitro fertilization-embryo transfer (IVF-ET). At 7 wk of gestation, the patient was referred to us due to abdominal pain accompanied by vomiting and hematochezia, and she was diagnosed with superior MVT. Following resection of the gangrenous portion of the small intestine, anticoagulation therapy with unfractionated heparin and thrombolysis therapy via a catheter placed in the superior mesenteric artery were performed, and the patient underwent an artificial abortion. Oral estrogen had been administered for hormone replacement as part of the IVF-ET procedure, and additional precipitating factors related to thrombosis were not found. Pregnancy itself, in addition to the administered estrogen, may have caused MVT in this case. We believe that MVT should be included in the differential diagnosis of a pregnant patient who presents with an acute abdomen.