Inner Myometrial Laceration Complicated by Severe Antepartum Haemorrhage: A Case Report and Literature Review

Abstract Background Inner myometrial laceration (IML) is a rare but potentially life-threatening obstetric emergency that can cause severe antepartum or postpartum haemorrhage. The pathogenesis of this condition is not fully understood, and this condition is often associated with abnormal uterine contractions, foetal position factors, or obstetric interventions. Its clinical manifestations are nonspecific, making early diagnosis difficult and leading to potential misdiagnosis or missed diagnosis. Case Presentation : This report describes a 26-year-old primigravida at 38⁺¹ weeks gestation who underwent oxytocin induction for preeclampsia. During induction, she presented with sudden massive vaginal haemorrhage, with an estimated blood loss of approximately 1200 ml. An emergency caesarean section revealed a 4 cm inner myometrial laceration on the posterior wall of the lower uterine segment, with the serosal layer intact. Haemostasis was successfully achieved using a "figure-of-8" suture combined with a continuous suture, supplemented with bilateral ligation of the ascending branches of the uterine arteries. The patient recovered well postoperatively, with no complications during follow-up, and her uterus was preserved. Conclusion IML is an important and occult cause of refractory antepartum or postpartum haemorrhage. Diagnosis relies on careful intraoperative exploration. Individualized suturing techniques and necessary vascular ligation are key to preserving fertility, whereas hysterectomy should be reserved as a last resort when conservative measures fail. Enhancing clinical vigilance for IML, early surgical exploration, and targeted repair is crucial for improving maternal and foetal outcomes.