Is it possible to predict the success of single dose methotrexate in the treatment of tubal ectopic pregnancies?

Objectives: In this study, the aim was to determine whether the use of endometrial thickness or neutrophil/lymphocyte and platelet/lymphocyte ratio would be useful in predicting the success of methotrexate in the treatment of ectopic pregnancies located in the fallopian tubes.

Materal and methods: This study was carried out by retrospectively examining 68 study group cases with an ultrasonographically detectable gestational sac in the fallopian tubes and 189 control group cases with an unruptured ectopic pregnancy diagnosis at any location. The cut-off value of endometrial thickness was calculated as a new marker between the cases in which single-dose methotrexate treatment was successful and the cases with treatment failure. Treatment success was evaluated with different models including endometrial thickness, fetal cardiac activity status, measurable crown-rump length, and β-hCG.

Result: The cut-off value of β-hCG for treatment success was determined as 2960.5 ng/mL, and the cut-off value for endometrial thickness was determined as 10.5 mm. Although NLR seems to be a marker with a cut-off value of 2.49, it does not provide an extra benefit in combined use as it is not a specific predictor. The highest success in predicting treatment success was achieved in the modeling in which crown-rump length + fetal cardiac activity + β-hCG + endometrial thickness were used together.

Conclusions: The use of endometrial thickness as a marker seems to be quite reliable in predicting treatment success. And we think it would be beneficial to thin the endometrium before using methotrexate.