Diagnostic challenges in cesarean scar ectopic pregnancy: case reports of rare entity

Introduction and importance: Cesarean scar ectopic pregnancy (CSEP) is a rare, potentially life-threatening condition characterized by implantation within or adjacent to a previous cesarean scar. Delayed or incorrect diagnosis may result in massive hemorrhage, uterine rupture, hysterectomy, loss of fertility, or maternal death. Presentation of cases: A 38-year-old gravida 3 para 2 with two previous cesarean deliveries presented at 17 weeks amenorrhea with lower abdominal pain worsened by intercourse. Transvaginal ultrasound showed a gestational sac implanted in the anterior lower uterine segment scar, without visible intervening myometrium between the sac and bladder. A 40-year-old gravida 7 para 6 with one previous cesarean delivery presented at 18 weeks with abdominal pain and vaginal bleeding. At 14 weeks, she had been diagnosed elsewhere with a presumed missed miscarriage and received misoprostol without expulsion of the pregnancy. Ultrasound subsequently demonstrated a non-viable CSEP. Both patients underwent emergency laparotomy and scar-pregnancy excision, followed by an uncomplicated recovery. Histopathology confirmed products of conception in Case 1 and placental tissue with acute chorioamnionitis in Case 2. Clinical discussion: CSEP can present variably and may be mistaken for an intrauterine miscarriage. Diagnosis requires careful assessment of the pregnancy’s relationship to the scar, uterine cavity, cervical canal, residual myometrium, and bladder. Miscarriage treatment should not begin until the location of the pregnancy is confirmed. Conclusion: Early recognition, referral, and detailed ultrasound are essential to reduce severe maternal morbidity, particularly where advanced imaging and interventional radiology are limited.