IDENTIFICATION OF HORMONAL PARAMETERS FOR SUCCESSFUL SYSTEMIC SINGLE-DOSE METHOTREXATE THERAPY IN ECTOPIC PREGNANCY

Single-dose methotrexate is an alternative to surgery in treating ectopic pregnancy, Because success rates vary, we sought to identify factors which predict treatment outcome, A total of 44 women with ectopic gestation were treated, The non-laparoscopic diagnosis of ectopic pregnancy was made following history, physical examination, ultrasound, endometrial biopsy and the measurement of serial beta-human chorionic gonadotrophin (HCG) and progesterone concentrations, Methotrexate (50 mg/m(2) i.m.) was administered, with a second dose given 1 week later in patients with plateauing or rising beta-HCG concentrations, Of 44 patients, 23 (52.3%) were successfully treated with one dose, An additional 10 women (22.7%) were also successfully managed but required a second dose, giving an overall success rate of 75.0%, In all, 11 women (25.0%) required surgery, four of whom experienced tubal rupture, Receiver operator curves were constructed to optimally select pretreatment beta-HCG and progesterone cut-off concentrations for successful treatment, Using beta-HCG <1500 IU/l or progesterone <7.0 ng/ml (22.3 nmol/l) as a cut-off concentration produced a diagnostic test with a sensitivity of 87.5%, a specificity of 90.0%, a positive predictive value of 96.6% and a negative predictive value of 69.2%. Conversely, this model predicts that patients with serum beta-HCG concentrations greater than or equal to 1500 IU/l and progesterone concentrations greater than or equal to 7.0 ng/ml are at far greater risk of failing single-dose methotrexate therapy.