Human chorionic gonadotropin levels 0/1-4 days after methotrexate administration for predicting ectopic pregnancy treatment success

INTRODUCTION: Ectopic pregnancy is one of the major causes of morbidity and mortality, accounting for 1 to 2% of all pregnancies. With the introduction of recent developments in diagnostic tools, the success rate of medical treatment has increased. The treatment is considered successful, if there is a 15% decline in serum human chorionic gonadotropin (hCG) levels between Days 4 and 7 of follow up in patients receiving single-dose methotrexate (MTX) treatment. In the present study, we aimed to determine whether the change in hCG levels between Days 0 and 4 is useful in predicting treatment success in patients receiving single-dose MTX protocol.
METHODS: A total of 93 patients who were diagnosed with ectopic pregnancy in our clinic between September 2016 and September 2018 and treated with MTX were retrospectively analyzed. The hCG levels of the patients on Days 0/1-4-7 were measured and recorded. Changes in hCG levels between Days 0/1-4 and 4-7 were calculated.
RESULTS: The overall success rate of single-dose MTX treatment was found to be 71.6%. A total of 50 patients of the success group had decreased hCG levels on Day 4, while only 18 patients of the success group had increased hCG levels on Day 4. Using the cut-off value for hCG change between Days 1 and 4, an increase of 16.1% in hCG levels was found to be the strongest predictor of treatment success. The sensitivity, specificity, and positive predictive value of this cut-off value were 89.7%, 64%, and 87.1%, respectively.
DISCUSSION AND CONCLUSION: In conclusion, early changes in hCG levels may be useful in the follow-up of the treatment success.