Pre-treatment patterns of human chorionic gonadotropin in ectopic pregnancy: Are they useful to predict the success of a single dose of methotrexate?

Study Objective: The aim of our study has been to evaluate whether pre-treatment patterns of HCG levels could be useful to identify patients with good or poor response to MTX therapy for ectopic pregnancy. Measurements and main results: A group of 62 patients was treated for ectopic pregnancy with a systemic single dose of Methotrexate (50 mg/m²) i.m. Samples for HCG detection were obtained on days-4, -2 and 0 before treatment and then kept under control until HCG levels disappeared completely. Persistence was observed in 14 cases. Patients were divided into three groups: Group UP (meaning: " increasing HCG levels") and Group DOWN (meaning: "decreasing HCG levels") when HCG levels on day 0 were respectively higher or lower than pre-treatment levels of more than 20% and Group PLATEAU when the difference between pre-treatment HCG levels and the level on day 0 was less than 20%. According to HCG levels on day-4 (n=52), all the patients of Group DOWN showed resolution of the condition, whereas the resolution rate in Group PLATEAU (60%) was lower than in Group UP (78,6% . Similar results were obtained considering HCG levels detected on day-2 (n=62): all the patients of Group DOWN showed complete resolution, whereas the resolution rate in Group UP and Group PLATEAU was respectively 80% and 68,6%. The differences between Group DOWN and Group PLATEAU appeared to be statistically significant (χ²) even considering day -4, even considering day -2 samples as pre-treatment level. Conclusions: The resolution rate after MTX therapy in patients with decreasing HCG levels resulted higher than in patients with increasing HCG levels. The lowest resolution rate was obtained in patients with stable pre-treatment level.