Clinical Presentation as a Predictor of the Response to Methotrexate Therapy in Patients with Ectopic Pregnancy.

Purpose: Ectopic pregnancy can be fatal if not diagnosed and timely treated. There is an increase in ectopic pregnancy rate which attributes in part to fertility medications and procedures and early diagnosis. Methotrexate, a folic acid antagonist, is widely used in the medical treatment of ectopic pregnancy. Many studies examined the safety and success rate of methotrexate looking into factors affecting the success rate, if the patient may present with symptoms such as abdominal pain, and some consider this as impeding rupture and it might affect the success of medical treatment. This study evaluates the success rate of methotrexate treatment outcomes in regard to presentation and looks into other factors that can help choosing a single or multiple dose modality.

Methods: This is a retrospective review of 154 cases of ectopic pregnancy treated with methotrexate from January 2011 to December 2020 at King Khalid University Hospital (KKUH). Demographic data, clinical presentation, treatment progress, and outcome and failure rate were collected and analyzed. Student's t-test was used for statistical analysis of associations in SPSS.

Results: 154 patients were treated with MTX; of those patients, 25 received more than one dose. The difference between the responses to MTX treatment in symptomatic and asymptomatic individuals was not significant (p = 0.267). 131 (85%) had successful treatment. There were no associations between patient BMI, ectopic mass size, or ectopic mass site, the presence or absence of pelvic fluid on ultrasound at diagnosis, and the treatment success rate. There was a significant decline in the treatment success rate with increasing β-hCG levels on the presentation day (p = 0.035) and on day 4 (p value <0.001) of treatment.

Conclusion: MTX treatment can be used to manage symptomatic patients with ectopic pregnancy. The success rate in symptomatic patients is not different from that in asymptomatic patients. β - hCG levels > 5000 IU/L. Pretreatment and on day 4 posttreatment is associated with higher failure rate.