Objective: To report a case of a methotrexate (MTX)-resistant heterotopic interstitial pregnancy in which dactinomycin was necessary as a second-line chemotherapy.
Design: Case report.
Setting: Medical college-affiliated hospital.
Patient(s): A 39-year-old woman with vaginal bleeding after the transfer of two thawed 8-cell embryos.
Intervention(s): MTX 50 mg/m(2) was given to the patient to treat a concomitant pregnancy in which an interstitial pregnancy and an intrauterine blighted ovum were identified. However, the patient's hCG level rose despite two MTX administrations. As a result, dactinomycin was then administered as a second-line chemotherapy. The patient's serum hCG level declined to a normal range after two administrations of dactinomycin.
Conclusion(s): Dactinomycin could be an alternative in cases for which MTX is not effective and persistently high hCG levels exist.