Outcome prediction for treatment of tubal pregnancy using an intramuscular methotrexate protocol.

Objective: The purpose of this study was to determine the outcome predictors of intramuscular methotrexate therapy for tubal pregnancy.

Methods: This retrospective study was approved by our Institutional Review Board. Fifty-five consecutive women (mean age, 31 years; range, 18-45 years) who were treated with intramuscular methotrexate therapy for tubal pregnancy were retrospectively reviewed. Clinical data (maternal age, gestational age, and serum beta-human chorionic gonadotropin [beta-hCG] level) and transvaginal sonographic findings (size, gross appearance, presence of a gestational product or heartbeat, and amount of the fluid collection) were assessed as potential predictors of the treatment outcome. The Fisher exact test was used for categorical variables, and the Wilcoxon signed rank sum test was used for continuous variables. Treatment failure was defined as the need for surgical intervention.

Results: Women with successful treatment differed from women with unsuccessful treatment with respect to the serum beta-hCG level, the gross appearance of tubal pregnancy, and the presence of a gestational product such as a yolk sac or embryo (P <.001; P = .01; and P =.008, respectively). All of the tubal pregnancies with a gestational product appeared as a tubal ring on transvaginal sonography. A high serum beta-hCG level of greater than 2390 mIU/mL and a transvaginal sonographic appearance of a tubal ring were the important predictors associated with failure of intramuscular methotrexate therapy for tubal pregnancy.

Conclusions: Measurement of the serum beta-hCG level and evaluation of the transvaginal sonographic appearance of tubal pregnancy are helpful for predicting treatment outcomes in women who receive intramuscular methotrexate therapy for tubal pregnancy.