When old scars tell new stories: A rare case report of cesarean scar ectopic

Background: Caesarean scar ectopic pregnancy (CSEP) is a rare but increasingly recognized form of ectopic implantation in which the gestational sac implants within the fibrous scar of a previous caesarean section. With the global rise in caesarean delivery rates and improved early pregnancy imaging, the reported incidence of CSEP has increased. Despite its rarity, this condition carries substantial maternal risk, including catastrophic hemorrhage, uterine rupture, progression to placenta accreta spectrum, and potential loss of fertility, underscoring the importance of early diagnosis and timely intervention. Case Presentation: We report the case of a 20-year-old gravida 2 para 1 woman with a prior caesarean section who presented with abdominal pain and amenorrhea. Transvaginal ultrasonography demonstrated a well-defined gestational sac located in the lower anterior uterine segment at the site of the previous caesarean scar, with marked thinning of the intervening myometrium between the sac and the urinary bladder and an empty upper endometrial cavity. An embryo measuring approximately 6.8 mm with a visualized yolk sac but absent cardiac activity was identified, consistent with a type II caesarean scar ectopic pregnancy. Pelvic magnetic resonance imaging confirmed implantation within the anterior lower uterine wall scar and provided detailed assessment of myometrial thinning, aiding preoperative planning. The patient subsequently underwent hysterotomy with successful removal of the ectopic gestation and had an uncomplicated postoperative recovery. Discussion: CSEP remains a diagnostic challenge owing to its variable clinical presentation and potential to mimic early intrauterine or cervical pregnancy. Transvaginal ultrasonography with adjunct colour Doppler is the cornerstone of diagnosis, while magnetic resonance imaging serves as a valuable complementary modality in equivocal cases and for evaluation of scar integrity and placental invasion risk. Conclusion: This case highlights the critical role of early imaging-based diagnosis in caesarean scar ectopic pregnancy. Prompt recognition and multidisciplinary management are essential to reduce maternal morbidity, prevent life-threatening complications, and preserve reproductive potential.