RESUMEN
PURPOSE: To present a case of an ectopic pregnancy in a previous caesarean scar in a woman who wishes to preserve her fertility, and its treatment with the local administration of potassium chloride (KCl) and methotrexate (MTX) via a transvaginal needle. CASE: A 35-year-old woman with a viable caesarean scar pregnancy was referred to our hospital. After an unsuccessful treatment attempt by administering 60 mg systemic methotrexate, the patient was treated with local administration of KCl and MTX using a transvaginal needle. The persistent ectopic mass was removed with dilatation and curettage (D&C) 1 week later. The patient had no complications and the treatment was successful in the follow-up examinations. CONCLUSION: Local MTX and KCl treatment using a transvaginal needle together with D&C can avoid unnecessary laparotomy, and helps to preserve the fertility of most women with a caesarean scar pregnancy.