Predictive factors of methotrexate treatment success in ectopic pregnancy: A single-center tertiary study

It is controversial whether medical or surgical treatment options have more successful results in ectopic pregnancy treatment. Although high pretreatment serum hCG levels have been known to be the most important predictor, the appropriate treatment modality for a specific range of hCG level remains unclear. Furthermore, the variables that make a patient a bad candidate for single-dose methotrexate treatment is unclear. The aim of this study was to identify predictive factors associated with the success of single-dose methotrexate treatment in women with ectopic pregnancy.

In this retrospective study, 101 women with tubal ectopic pregnancies who had been treated with single-dose methotrexate were selected. The gestational ages, pretreatment hCG values, ectopic mass size, and fluid presence in the abdomen were compared between the groups.

The mean age of the patients was 30.6±5.8 (range, 19-42) years, and the gestational age at first injection was 7.0±2.13 (range, 2.3-13.6) weeks. The overall treatment success rate was 77.2% (n=79). The mean duration of hospital stay was 4.21±1.89 days in the successfully treated group and 6.92±2.13 days in the failure group (p<0.05). The rate of treatment failure in patients with abdominal fluid was 37.8%, and it was 12.7% in the non-fluid group (p=0.03). hCG values on days 1, 4, and 7 were significantly higher in the unsuccessful group (3887-2589 mIU/mL, 2814-1287 mIU/mL, and 1119-285 mIU/mL, respectively; p<0.05). The cutoff hCG value, which determined the failure of methotrexate treatment, was found to be 1362 mIU/mL.

In present study, patients with hCG value <1362 mIU/mL were found to be good candidates for methotrexate treatment. Although not strictly decisional, this hCG threshold level can be used to decide on the likelihood of methotrexate success or failure. Detection of abdominal fluid on ultrasonography also can be assessed as a bad prognostic factor, but size of ectopic mass does not correlate with methotrexate treatment success.