Evaluation of the parameters in predicting single-dose methotrexate therapy success for ectopic pregnancy.

AIM: Methotrexate has demonstrated efficacy in treating ectopic pregnancies. This study explores factors influencing treatment success, focusing on laboratory and ultrasonographic findings, particularly the day 4 to day 1 β-hCG level ratio.

METHODS: Retrospective cohort study was conducted within patients diagnosed with tubal ectopic pregnancy. Patients' characteristics, ultrasound findings, laboratory data, and β-hCG levels (days 1, 4, 7), and operation findings were reviewed. Women's characteristics were investigated who were treated with single dose of MTX (50 mg/m2 ). Patients who were performed surgery after MTX treatment were identified as MTX treatment failure.

RESULTS: Among 439 women, 259 underwent surgery due to acute symptoms. Of those treated with MTX, 143 experienced treatment success, while 37 underwent surgery after MTX (MTX failure). Comparative analysis revealed significant differences in β-hCG levels on admission (1128 and 4125 mIU/mL) and the day 4 to day 1 β-hCG ratio (0.91 and 1.25). The overall MTX success rate was 79%, reaching 93% and 89% for β-hCG levels <1000 mIU/mL and <2000 mIU/mL, respectively. Success dropped to 50% with levels exceeding 5000 mIU/mL. ROC analysis identified a crucial 2255 mIU/mL cut-off for β-hCG (sensitivity 70.3% and specificity 68.5%) and a day 4 to day 1 β-hCG ratio of 95.5% (sensitivity 84.7%, specificity 72.5%, positive predictive value 75.4%) for predicting MTX success.

CONCLUSION: Establishing a β-hCG cutoff can reduce hospital stay. The day 4 to day 1 β-hCG ratio holds promise as a widely applicable predictor for MTX success or for determining MTX administration on day 4.