Uterine didelphys presenting as pelvic organ prolapse and second trimester uterine rupture: a case series and literature review.

Background: Uterine didelphys is a very rare Mullerian duct anomaly resulting from complete failure of ductal fusion, leading to duplication of uterine horns, cervix, and sometimes the proximal vagina. Although many of them are asymptomatic, it can present as poor reproductive outcomes or, rarely, pelvic organ prolapse. Reports of obstetric rupture in early gestation or prolapse in a didelphic uterus are exceedingly rare. Case presentation: We present two contrasting cases that present differently in a didelphys uterus. First, a 26-year-old primigravida initially had an unexplained massive hemoperitoneum at 17 weeks of gestation. One uterine horn of a didelphys uterus ruptured during an emergency laparotomy, resulting in expulsion of the fetus and the placenta into the peritoneal cavity. This required a supracervical hysterectomy of the ruptured horn. The second case describes a 50-year-old postmenopausal woman with a 5-year history of vaginal mass and urinary symptoms. She was preoperatively diagnosed with third-degree uterovaginal prolapse and underwent transvaginal hysterectomy, during which a didelphic uterus was unexpectedly identified. Both patients recovered uneventfully after surgery. Clinical discussion: These cases illustrate the diagnostic and intraoperative challenges of uterine didelphys. In the obstetric case, the anomaly was identified solely post-rupture, whereas in the gynecologic case, it was detected incidentally during prolapse surgery. Conclusion: Uterine didelphys can present across a wide spectrum - from life-threatening rupture to chronic prolapse. Clinicians should maintain a high index of suspicion in atypical presentations and be prepared for unexpected anatomy to ensure safe, individualized management.