Abstract
Background: Early diagnosis and emergency management is essential to avoid significant bleeding, uterine rupture, and increased risk of maternal mortality in the ectopic cesarean scar pregnancy (CSP).
Case presentation: A 33-year old Saudi patient G7 P4 + 2 was presented to emergency department with vaginal bleeding for 1 day at 8th week of pregnancy. The patient had a history of four cesarean deliveries. Her most recent pregnancy was 4 years prior to her presentation. Pelvic examination showed closed cervix. Laboratory investigations were normal. Beta human chorionic gonadotropin (β-hCG) was 103,517 mIU/ml at presentation. Ultrasound showed that gestational sac (GS) was low in position at level of caesarean section (CS) scar and fetal heart sound (FH) was positive. The diagnosis of ectopic CS scar pregnancy was done. Methotrexate 100 mg intramuscular (IM) was started. On 2nd day, β-hCG raised to 121,531 mIU/ml. The patient received the second dose on 4th day. β-hCG raised to 125,385 mIU/ml. Ultrasound showed the area of separation of the GS and FH+. After 1 week, the patient received the third dose of methotrexate local embryocidal injection. By next day, β-hCG dropped to 83,633 mIU/ml. Ultrasound showed FH-. On the 9th day, the patient was completely well and β-hCG dropped to 826 mIU/ml.
Conclusion: Clinicians should be aware of the diagnosis and management of CSP. CSP remains rare but might lead to severe uncontrolled bleeding, increase risk of maternal mortality, and future infertility. Early diagnosis and treatment are important for the best outcome.

Key words: Cesarean scar pregnancy, ectopic pregnancy, case report, methotrexate, suction evacuation.