Comparison of alternative βhCG follow-up protocols after single-dose methotrexate therapy for tubal ectopic pregnancy.

Purpose: To evaluate the performances of five different βhCG follow-up protocols after single-dose methotrexate therapy for tubal ectopic pregnancy (EP).

Methods: Data of patients who received single-dose methotrexate therapy for tubal EP at a university hospital between January 2011 and July 2016 were reviewed. A 'successful methotrexate treatment' was defined if the EP treated with no need for surgery. The performances of different protocols were tested by comparing with the currently used '15% βhCG decrease between days 4 and 7' protocol. The tested follow-up protocols were '20, 25%, and any βhCG decrease between days 0/1 and 7' and '20% and any βhCG decrease between days 0/1 and 4'.

Results: Among the 96 patients evaluated, 12 (12.5%) required second dose. Totally, 91 (94.8%) patients treated successfully with no need for surgery. Four patients were operated within 4 days following the second dose. One patient who did not need second dose according to the standard follow-up protocol was operated on the 10th day due to rupture (specificity = 80%). Two protocols, namely '20% βhCG decrease between days 0/1 and 7' and 'any βhCG decrease between days 0/1 and 7' did not show statistically significant differences from the index protocol regarding the number of patients who should be assigned to 2nd dose.

Conclusions: 'Any βhCG decrease between days 0/1 and 7' protocol may substitute the currently used one to decide second dose methotrexate in tubal EP management. Omitting 4th day measurement seems to be more convenient and cost effective.