Single-dose methotrexate for the treatment of unruptured ectopic pregnancy

The objective of this study was to review our experience with single dose intramuscular methotrexate (MTX) for the treatment of ectopic pregnancy and to evaluate major confounding factors that relate to the success of therapy.

The selection criteria were patients who had a stable hemodynamic status and an ectopic gestational mass of <4 cm. on ultrasound. Patients were not excluded from MTX therapy either by a baseline serum β-hCG titer or by the presence of fetal cardiac activity demonstrated on ultrasonography. Thirty- four of 86 patients diagnosed with ectopic pregnancy and treated with single-dose MTX between July 1999 and November 2001 were reviewed retrospectively.

The mean pre-treatment β-hCG level was 2,490±2,912 mIU/ml. Twenty-two patients (73.3%) were successfully treated with a single-dose of MTX. Eight patients (26.6%) required a second dose 1 week after the first injection and 2 patients received three doses. Thirty of the 34 patients (88%) were successfully treated with MTX. The mean pre-treatment β-hCG level was significantly lower in patients who were successfully treated with MTX than in patients who failed MTX therapy (1,932±2,361 mIU/ml vs. 6,955±2,690 mIU/ml respectively, p<0.05). The mean pre-treatment serum β-hCG level was higher in patients who had a second MTX injection as compared to patients who were successfully treated with a single injection of MTX (3,272±3,551 mIU/ml vs. 1,280±2,273 mIU/ml respectively, p>0.05). The mean time to resolution of β-hCG was 26.5 days (10 to 37 days) with MTX. All 3 patients who failed medical therapy had β-hCG level >4,000 mIU/ml and 2 of them had positive fetal cardiac activity.

In conclusion, this study showed that medical treatment of ectopic pregnancy with systemic single-dose methotrexate seems to be an option for some patients with unruptured tubal pregnancy.