Early prediction for the requirement of second or third dose methotrexate in women with ectopic pregnancy, treated...

To investigate the predictive factors for the requirement of additional doses of methotrexate in women with ectopic pregnancy treated with single-dose methotrexate regimen.

This retrospective cohort study was conducted on women treated with single-dose methotrexate regimen for ectopic pregnancy at a tertiary referral center. Control group included the patients who were treated only with a single dose of methotrexate (n = 131) and study group included the patients who need a second dose or third dose methotrexate (n = 76). The sonographic variables such as size of the ectopic mass, the endometrial thickness and biochemical variables were analyzed via Chi square and student t test. Logistic regression analysis used to determine independent predictors of the additional dose requirement.

The size of the ectopic mass and the endometrial thickness were similar in both groups. However, all human chorionic gonadotropin values on day 1, 4 and 7 were significantly higher in study group than the control group (p = 0.0001). Logistic regression analysis revealed that the human chorionic gonadotropin changes between day 1 and 4 is a predictive factor for requirement of additional doses of methotrexate (area under curve: 0.763, p < 0.001) and the cutoff value for human chorionic gonadotropin change was calculated as 22%. The probability of the requirement for an additional dose of methotrexate is 6.45 times more in patients who had less than 22% reduction in human chorionic gonadotropin levels from day 1 to 4 compared to those who had >22% reduction from day 1 to 4.

Less than 22% reduction in human chorionic gonadotropin levels from day 1 to 4 can be used as a predictive factor for the requirement of an additional dose of methotrexate in single-dose regimen. This cutoff value can be used for patients to inform about the probable longer resolution time and refer to alternative treatment modalities such as two-dose, multiple-dose regimens or surgery.