Beyond the Ordinary: Diagnostic and Surgical Challenges in a Rare Mullerian Anomaly

Objective: To describe a rare and complex Mullerian anomaly initially misclassified in pregnancy. This case highlights the diagnostic challenges and obstetric outcomes of a complete septate uterus with duplicated cervices and longitudinal vaginal septum during pregnancy. Design: A case report at Promedica Hospital, Toledo, Ohio. Materials and Methods: The case was evaluated through a retrospective review of the patient’s medical records, including imaging studies, maternal fetal medicine evaluations, operative findings, and obstetrical outcomes. Results: A 30 year old G1P0 woman presented with infertility. Initial workup with transvaginal ultrasound revealed a bicornuate versus arcuate uterus. Follow up MRI showed a septate uterus extending into the cervix. During this time the patient conceived spontaneously. A maternal fetal medicine ultrasound obtained during pregnancy suggested a bicornuate bicollis uterus with a uterine septum down to the cervix, with two cervices, and pregnancy in left horn. At 20 weeks’ gestation, cervical insufficiency was diagnosed in left cervix, measuring 0.75cm and the right cervix was normal, 2.96cm. A McDonald cerclage was placed in the cervix of the gravid uterine horn. At 24 weeks gestation the patient presented with preterm labor. Examination revealed dilation of the non-gravid cervix with protruding tissue from gravid uterus, ultimately identified as decidualized tissue on pathology. Due to progressive labor and fetal heart rate abnormalities, the fetus was delivered via classical cesarean section at 24w4d gestation. Intraoperative findings were consistent with prior exams, MRI and ultrasound imaging, with final diagnosis of complete uterine septum with duplicated cervices and a longitudinal vaginal septum. Conclusions: Complex Mullerian anomalies can be difficult to accurately diagnose using imaging alone, and misclassification may occur between variants. Careful correlation of imaging with physical examination and intraoperative findings is essential. This highlights the rare presentation of a complete septate uterus with duplicated cervices and longitudinal vaginal septum, as well as potential association with preterm delivery. Diagnosis is important for counseling, pregnancy management, and future reproductive planning.