ß-hCG and prediction of therapeutic success in ectopic pregnancies treated with methotrexate, results from a prospective observational study.

To evaluate the diagnostic accuracy of different beta-human chorionic gonadotrophin (ß-hCG) levels measurement, for predicting success of medical treatment in cases diagnosed as tubal ectopic pregnancy (TEP). Five-year prospective observational study. Prenatal Diagnosis Unit, Vall d'Hebron University Hospital - Barcelona. TEP cases fulfilling criteria for medical treatment with Methotrexate. ß-hCG levels were measured on d 0, 4 and 7 of treatment. Results were compared by non-parametrical tests. A ROC curve was plotted to define cut-off points. Diagnostic accuracy of the different measurements was evaluated. Failure of treatment defined as need for surgical treatment or persistence of high ß-HCG levels despite treatment. 126 women were diagnosed as TEP, eligible for medical treatment. There were no differences in parity, age, previous TEP, or adnexal mass size. Success rate was 88%. ß-HCG decreased significantly more, between days 0-7 and 4-7, in the successful cases. LR for success prediction was 6.2 and 7.8 for ß-HCG levels at days 4 and 7 respectively, 4.02 and 2.47 for decrement between days 0-7 (25%) and 4-7 (20%), respectively. ß-hCG cutoff values have a potential for predicting a successful medical treatment of TEP.