Unscarred uterine rupture with catastrophic hemorrhage immediately after vaginal delivery: diagnosis and management of six consecutive cases

Background: To describe and explore the risk factors, clinical presentations, timely diagnostic approaches, and management in patients experiencing unscarred uterine rupture with catastrophic hemorrhage. Methods: We retrospectively analyzed clinical and imaging data from women who encountered postpartum hemorrhage (PPH) and were diagnosed with unscarred uterine rupture within a three-year timeframe (2018-2020). The data were extracted from medical records obtained from a multi-hospital 24-hour emergency PPH transfer system. Results: Six patients were identified as having unscarred uterine rupture after vaginal delivery. All six women were para 2, with four of them undergoing vacuum-assisted delivery. One patient experienced out-of-hospital cardiac arrest (OHCA), while five patients presented with hypovolemic shock. Abdominopelvic ultrasound revealed a boggy lower uterine segment. Initially, five patients underwent transarterial embolization (TAE) of the internal iliac arteries in an attempt to achieve hemostasis, but this approach proved unsuccessful. Abdominopelvic computed tomography (CT) confirmed the diagnosis of ruptured uterus by demonstrating disrupted myometrium and hemoperitoneum. Immediate exploratory laparotomy followed by life-saving hysterectomy was performed in all cases. The median estimated total blood loss was 2725 mL ± 900 mL (ranging from 1600 mL to 7100 mL). Lower segment lacerations were observed in all patients, with more extensive uterine damage noted in those who underwent vacuum extraction. The length of hospital stay varied between 9 and 38 days. Conclusion: Instrument-assisted obstetric delivery is a possible contributing factor to unscarred uterine rupture in our study. In specific cases, the use of abdominopelvic CT prior to initiating transarterial embolization (TAE) offers valuable information to complement ultrasound findings. This comprehensive approach helps in accurately identifying the underlying cause of intractable postpartum hemorrhage (PPH). Immediate conversion to laparotomy is essential to explore the intra-abdominal factors causing PPH that cannot be controlled by TAE. The rational etiologies of uterine rupture must be clarified while generating practical guideline in the future.