Primary omental pregnancy: case report and review of literature.

Omental pregnancy is a very rare form of ectopic pregnancy. A 29-year-old woman presented with severe abdominal pain. History of the patient revealed use of combined oral contraceptive pills. There was no gestational sac in the endometrial cavity and no tubal ring in the adnexa, but free peritoneal fluid was detected at ultrasonography. Laparotomy was done according to pre-operative diagnosis of ruptured tubal pregnancy. Bilateral tubes and ovaries were intact; gestational sac was detected attached to the necrotic lower edge of omentum. Although 16 cases of omental pregnancy (mostly secondary) were reported in the literature, herein we describe a primary omental pregnancy without adnexal involvement.