Scar niche pregnancy successfully managed by laparotomy and excision of a caesarean scar ectopic pregnancy

Abstract

Caesarean scar pregnancy (CSP) is a rare form of ectopic pregnancy in which the gestational sac implants within a previous caesarean section scar. Its recognition is increasing with rising caesarean delivery rates and improved ultrasonography. Transvaginal ultrasonography is the primary diagnostic modality, assessing gestational sac location and residual myometrial thickness. Management depends on gestational age, clinical stability, and fertility preferences, with options including medical therapy and surgical intervention. Early diagnosis and appropriate treatment are essential to prevent haemorrhage, uterine rupture, and other serious maternal complications while preserving fertility. A 31-year-old woman, G3P1L1A1, presented at approximately 7 weeks of gestation with vaginal spotting without abdominal pain or discomfort. She had a history of one caesarean delivery four years earlier and suction and evacuation for abortion seven months previously. Transvaginal ultrasonography revealed a caesarean scar ectopic pregnancy, with the gestational sac predominantly within the scar niche, a crown–rump length of 3.4 mm, and residual myometrial thickness of approximately 2.1 mm. Her serum β-hCG was 13,895 mIU/ml, and haemoglobin was 8.6 g/dL. After transfusion of two units of packed red blood cells, she initially received two intramuscular doses of methotrexate (50 mg) with leucovorin rescue. However, β-hCG increased to 14,554 mIU/ml on day 4, prompting surgical intervention. Laparotomy revealed a 2-cm bulge at the previous caesarean scar. The ectopic pregnancy was evacuated vaginally under direct supervision, followed by excision of the scar and two-layer uterine repair. The patient tolerated the procedure well. There has been an increase in scar ectopic pregnancy cases alongside rising caesarean section rates. Various medical and surgical treatments have been explored, but no consensus exists on the best approach. The authors advocate for laparotomy with scar ectopic tissue excision, especially in resource-limited settings lacking advanced technology or expertise.