Emergent Intervention of a Non-Communicating Rudimentary Uterine Horn Pregnancy

Abstract

Background: Non-communicating rudimentary uterine horns (NRCH) arise from Mullerian duct malformations during embryonic development. Pregnancies of the rudimentary horn account for 0.0013% to 0.00067% of all pregnancies. Such pregnancies are non-viable and pose major risks to the mother. Without early detection and management, maternal mortality rates can be as high as 88% due to rupture.

Case Description: A 22-year-old G1P0 female at 7 weeks gestation presented to the emergency department with abdominal pain for 3 weeks. A transvaginal ultrasound (TVUS) was performed and a fetal pole with cardiac activity was seen in the right adnexa, suspicious for ectopic pregnancy. She had an unremarkable TVUS 1 year ago. A diagnostic laparoscopy was performed for presumed treatment of ectopic pregnancy. During the procedure, patient was found to have a right non-communicating rudimentary uterine horn with pregnancy noted inside. The left horn was connected to the cervix and otherwise normal. Intraoperatively, the right ureter was not identified. Due to high risk of rupture, the rudimentary right horn with pregnancy and the right fallopian tube were resected. A postoperative CT urogram revealed a solitary renal kidney and single left ureter.

Clinical Significance: The high mortality rate of ruptured NCRH pregnancies highlights the importance of early detection and proper management of such pregnancies. Mullerian duct anomalies are usually detected with ultrasound or magnetic resonance imaging prior to conception. In this case, the NRCH was formerly unknown and treated as an ectopic pregnancy with fetal cardiac activity. The complete resection of the rudimentary horn with pregnancy and fallopian tube proved to be an appropriate management for this emergent situation.

Conclusion: In emergent situations of an undetected NRCH until pregnancy, resection of rudimentary horn with ipsilateral fallopian tube is not only therapeutic, but also preventative for potential future ectopic pregnancies.