Methotrexate-treated ectopic pregnancy: beta human chorionic gonadotropin serum changes as a success predictor using a mathematical model validation

Our data support that negative β-hCG relative changes on the 4th day of treatment likely predict a successful result of methotrexate therapy, with a cut-off point of 0.15. Expectant management should be carried out in these cases if no clinical indications of surgery are presented.