BACKGROUND: Interstitial (cornual) pregnancy is a rare and life-threatening disease. Although systemic treatment with methotrexate (MTX) in an unruptured interstitial pregnancy has been used to preserve the entirety of the uterus, surgery is often used as a rescue method in failed cases. Use of an ultrasound-guided local injection can be a good alternative to surgery. CASE: A 30-year-old woman, gravida 1, para 0, with an interstitial pregnancy at 10 weeks of gestation, was successfully treated with an ultrasound-guided 100-mg MTX injection after a failed response to 3-dose intramuscular 100-mg MTX treatment (300 mg in total). Regular menstruation occurred 1 month after the local MTX injection. The serum beta-human chorionic gonadotropin level was undetectable 49 days later, and the residual mass had disappeared 6 months later, CONCLUSION: Local injection of MTX may be a good means of managing an unruptured interstitial pregnancy to preserve the entirety of the uterus after failed systemic MTX treatment. Use of a local MTX injection may be a better choice than that of systemic MTX treatment.
BACKGROUND: Interstitial (cornual) pregnancy is a rare and life-threatening disease. Although systemic treatment with methotrexate (MTX) in an unruptured interstitial pregnancy has been used to preserve the entirety of the uterus, surgery is often used as a rescue method in failed cases. Use of an ultrasound-guided local injection can be a good alternative to surgery. CASE: A 30-year-old woman, gravida 1, para 0, with an interstitial pregnancy at 10 weeks of gestation, was successfully treated with an ultrasound-guided 100-mg MTX injection after a failed response to 3-dose intramuscular 100-mg MTX treatment (300 mg in total). Regular menstruation occurred 1 month after the local MTX injection. The serum beta-human chorionic gonadotropin level was undetectable 49 days later, and the residual mass had disappeared 6 months later, CONCLUSION: Local injection of MTX may be a good means of managing an unruptured interstitial pregnancy to preserve the entirety of the uterus after failed systemic MTX treatment. Use of a local MTX injection may be a better choice than that of systemic MTX treatment.