Pregnancy in Non-communicating Rudimentary Horn

Background: Pregnancy in the rudimentary horn of the unicornuate uterus is highly rare. Its incidence is 1 in 75000-150000 pregnancies. It is difficult to diagnose the rudimentary horn of the unicornuate uterus before the rupture of an ectopic pregnancy. Case Presentation: The current study reports the case of a 35-year-old Iranian mother with a natural contraceptive method. The mother was a primigravida woman at the gestational age of 7 weeks, based on her last period. She complained of abdominal pain in the right and lower abdomen and had a positive pregnancy test with a beta-human chorionic gonadotropin beta-human chorionic gonadotropin (beta-hCG) titration of 38982 on May 17, 2021. The ultrasound report on May 17, 2021, showed a right adnexal mass with a size of 32*32*31 and a fetal pole, and yolk sac. A fetal heart of six weeks and one day in favor of ectopic pregnancy was detected. and its endometrial thickness was 12 mm. There were no abdominal or pelvic-free fluids. Thus, after being diagnosed with an ectopic pregnancy that included a heart, the patient was transferred to the operating room for laparoscopy. During laparoscopy, we found that the pregnancy was in the rudimentary horn of the unicornuate uterus. The rudimentary horn was resected, and the salpingectomy of the right side was performed for the patient. The samples were then transferred to the laboratory for pathological analysis. Conclusion: We should increase awareness about pregnancies that occur in this uterine abnormality so that there is a high suspicion index for faster diagnosis before the rupture of ectopic pregnancy and worse events can be prevented accordingly.