A case of retroperitoneal ectopic pregnancy following IVF-ET in a patient with previous bilateral salpingectomy.

The numbers of ectopic pregnancies have increased because of the popularization of assisted reproductive techniques. However, the retroperitoneal space is an exceptional location for ectopic pregnancy because the entrance to the retroperitoneal space is unknown. A woman 31 years of age who had received bilateral salpingectomy because of a right tubal ectopic pregnancy and a left hydrosalpinx 4 years earlier was treated by in vitro fertilization and embryo transfer (IVF-ET). Ultrasonography and magnetic resonance imaging (MRI) revealed a gestational sac attached to the inferior vena cava in the midabdomen of the retroperitoneal space. Single-dose methotrexate administration was administered twice. However, because of sudden upper abdominal pain with a drastic decline of hemoglobin, an emergent laparotomy was performed. The hematoma and a gestational sac were removed from the aorta and inferior vena cava. Ectopic pregnancy following IVF-ET in a patient with bilateral salpingectomy is likely to be the cause of implantation at this unusual site. An unusual ectopic pregnancy has a high risk of life-threatening massive bleeding. Intensive transabdominal ultrasound scanning and whole abdominal MRI should be performed for the early diagnosis of unruptured ectopic pregnancy.