Single-dose methotrexate for the treatment of ectopic pregnancy: Northwestern Memorial Hospital three-year experience

Our purpose was to evaluate the effectiveness of single-dose intramuscular methotrexate in the treatment of ectopic pregnancies by physicians in the Department of Obstetrics and Gynecology of Northwestern Memorial Hospital and to compare the results with those of previously published studies.

A retrospective chart review was performed of 50 patients with ectopic pregnancies treated with single-dose methotrexate according to the protocol of Stovall et al. from January 1992 to February 1995.

The mean pretreatment level of beta-human chorionic gonadotropin was 1896.4 +/- 2399 mlU/ml. Only 32 women (64%) were successfully treated with a single dose of methotrexate. An additional 7 women required a second or third injection. The combined success rate for medical management of ectopic pregnancy with one to three doses of methotrexate was 78% (39 women). Pretreatment beta-human chorionic gonadotropin levels were significantly lower in women who responded to single-dose therapy than in those who required either two or three doses or who had failure of medical management (p = 0.0011). The mean time to resolution of beta-human chorionic gonadotropin was 26.5 +/- 17 days. Higher pretreatment levels correlated with longer resolution time (r = 0.83, p < 0.001). Eleven women (22%) with failure of medical management required surgery.

In our series single-dose methotrexate was only 64% successful. Women with a pretreatment beta-human chorionic gonadotropin level >5000 mlU/ml had a greater probability of requiring either surgical intervention or multiple doses of methotrexate. The potential for emergency surgery remains an important risk.