Experience With Medical Treatment of Cesarean Scar Ectopic Pregnancy (CSEP) With Local Ultrasound-Guided Injection of Methotrexate

Objective: Ectopic pregnancy within Cesarean section scars is a rare condition. Late diagnosis carries significant risk of bleeding with poor prognosis for survival. There is no consensus on the management of this type of pregnancy. Historically, our facility offered an intra-muscular injection of methotrexate that resulted in a significant failure rate and later need for surgery. We hypothesized that injecting methotrexate directly into the gestational sac would improve the success rate of the treatment. Patients and Methods: This retrospective, uni-centric study examined nine patients aged between 33 and 42 years (mean age = 36.5 years) with Cesarean scar ectopic pregnancy (CSEP) between 2010 and 2018. CSEP was diagnosed by transvaginal ultrasound at a mean gestational age of 8w0/7. CSEP was treated under general anesthetic by ultrasound-guided methotrexate injection directly into the gestational sac. HCG levels and subsequent childbearing were monitored post-treatment. Results: Half of the patients were asymptomatic at the time of diagnosis. All patients tolerated treatment well and all ectopic pregnancies were successfully removed. HCG levels returned to negative within 3 months without additional medical or surgical intervention. The post-treatment pregnancy rate was 50%. Discussions/Conclusions: Our findings indicate that local ultrasound-guided injection of methotrexate into the gestational sac is a safe and effective therapeutic approach when performed by a trained team on a hemodynamically stable patient in the early stages of CSEP.