Management of Cesarean Scar Ectopic Pregnancy with Systemic Methotrexate and Ultrasound-Guided Intra-Gestational Sac Injection

Background: Cesarean scar ectopic pregnancy (CSEP) is a rare condition that occurs when an early pregnancy (blastocyst) implants into the fibrous scar tissue of a previous cesarean section hysterotomy. CSEPs are managed on a case-by-case basis as there is not a standardized treatment approach. Methods: The authors evaluated the treatment of cesarean scar ectopic pregnancies CSEP using a promising technique of daily alternating methotrexate and leucovorin followed by, if necessary, a minimally invasive approach using ultrasound-guided intra-gestational sac injection of potassium chloride (KCl) through a literature review and cases from our urban community hospital. Data was collected from 22 cases, 17 from our literature review and five from our urban community hospital, where both methotrexate and intra-sac KCl injection were used to treat CSEP. Results: 19 of the 22 patients (86%) had successful resolution of their CSEP without further intervention. Conclusion: We find that daily alternating methotrexate and leucovorin followed by a minimally invasive approach using ultrasound-guided intra-gestational sac injection of KCl is an effective CSEP treatment and is associated with fewer complications and additional required interventions compared to the most commonly reported procedure of administering methotrexate after KCl instillation. Additionally, this procedure is uterine-preserving for future fertility and was found to have minimal maternal adverse effects.