Efficacy of In Situ Methotrexate Injection in the Treatment of Nontubal Ectopic Pregnancies: A Retrospective Multicenter Study

Abstract

Study objective: Evaluation of the efficacy of different injection sites of methotrexate in the treatment of nontubal ectopic pregnancies.

Design: Retrospective multicenter study.

Setting: Multicenter, including 3 teaching hospitals, an intercommunal hospital, and a clinic.

Patients: A total of 106 patients with nontubal ectopic pregnancies, including 59 interstitial, 39 cesarean scar, and 8 cervical or isthmic.

Interventions: Overall, 58 patients received methotrexate via intramuscular injection (IM group), 35 received methotrexate via in situ injection (IS group), and 13 received a combination of both in situ and intramuscular injections of methotrexate (IS + IM group).

Measurements and main results: The main end point of this study was measured via the primary success rate (defined as a negative β-human chorionic gonadotropin level without recourse to any additional treatment) of treatment with methotrexate according to injection site. The primary success rate was 46.55% in the IM group, 60% in the IS group, and 61.54% in the IS + IM group, respectively. In the multivariate analysis, the primary success rate of treatment was significantly correlated to the in situ injection of methotrexate, either solely or in conjunction with an intramuscular injection of methotrexate administered the following day, (odds ratio = 2.7; 95% confidence interval, 1.03-7.14).

Conclusion: Solely an intramuscular injection of methotrexate is a less efficient first-line treatment strategy for the conservative management of nontubular ectopic pregnancy. The use of an in situ injection of methotrexate should therefore be preferred.

Keywords: Conservative medical treatment; Extrauterine pregnancy; Intramuscular methotrexate injection.