Advanced Gestational Caesarean Scar Pregnancy Presenting with Impending Uterine Rupture: Diagnostic Challenges in a Late Presentation

Abstract Caesarean scar pregnancy (CSP) is a rare but increasingly recognized form of ectopic pregnancy in which implantation occurs within the fibrous tissue of a previous caesarean section scar. With rising caesarean delivery rates, the incidence of CSP is increasing. It may closely mimic other obstetric emergencies clinically and radiologically, especially in advanced gestation, making diagnosis challenging. Early recognition is critical due to the high risk of catastrophic haemorrhage, uterine rupture, and maternal morbidity. We present a diagnostically complex and life-threatening case of a 25-year-old gravida 3 para 1 living 1 abortion 1 (G3P1A1L1) at 22+6 weeks of gestation, with a history of previous lower segment caesarean section, who presented with acute abdominal pain and heavy vaginal bleeding. On presentation, the patient was hemodynamically unstable with severe pallor and abdominal tenderness. Ultrasonography revealed a low-lying gestational sac at the site of the previous caesarean scar with marked thinning of the anterior myometrium and increased vascularity, suggestive of caesarean scar pregnancy with features of impending uterine rupture. An emergency exploratory laparotomy was performed in view of ongoing haemorrhage and maternal instability. Intraoperatively, the lower uterine segment was found to be grossly thinned and distended with placental tissue densely adherent to the previous caesarean scar. Active bleeding was noted, and conservative measures failed to achieve haemostasis. A subtotal hysterectomy was performed as a life-saving procedure. The patient required massive blood transfusion but recovered well postoperatively and was discharged in stable condition. This case highlights the importance of early antenatal diagnosis of caesarean scar pregnancy, especially in women with previous caesarean deliveries. Delayed diagnosis in resource-limited settings can lead to severe maternal morbidity. Increased clinical vigilance, early ultrasonographic evaluation, and timely surgical intervention are essential to improve maternal outcomes.