Ruptured rudimentary horn pregnancy diagnosed by preoperative magnetic resonance imaging resulting in fetal salvage

Pregnancy in a rudimentary horn is very rare. The rupture of the horn during pregnancy is an obstetric emergency which can be life-threatening for both the mother and fetus. Preoperative diagnosis of such pregnancies can be challenging and they are usually diagnosed intraoperatively. We report a unique case of a 31-year-old multiparous woman who presented to the Sultan Qaboos University Hospital in Muscat, Oman, in January 2013 at 32 gestational weeks with abdominal pain. Ultrasonography was inconclusive. A rudimentary horn pregnancy was subsequently diagnosed via magnetic resonance imaging (MRI). An emergency laparotomy revealed haemoperitoneum and a ruptured rudimentary horn pregnancy. A live baby with an Apgar score of 2 at one minute and 7 at five minutes was delivered. The rudimentary horn with the placenta in situ was excised and a left salpingooophorectomy was performed. The postoperative period was uneventful. The authors recommend MRI as an excellent diagnostic modality to confirm rudimentary horn pregnancies and to expedite appropriate management.