Retroperitoneal ectopic pregnancy: successful expectant management in condition of early pregnancy failure.

In addition to transvaginal and transabdominal ultrasound, MRI is necessary for the diagnosis of nonviable REP. Alongside the great vessels in the abdominal cavity should be taken into consideration in all suspected cases relating to this rare entity. Expectant management may be carefully indicated in conditions of nonviable REP and unruptured REP, where applicable.