Routine β-Human Chorionic Gonadotropin Monitoring for Single-Dose Methotrexate Treatment in Ectopic Pregnancy

Abstract

Study objective: To evaluate an alternative monitoring protocol without day 4 β-human chorionic gonadotropin (β-hCG) measurement for predicting the need for a repeated methotrexate (MTX) dose in patients undergoing single-dose MTX therapy for ectopic pregnancy (EP).

Design: Single-center retrospective study (Canadian Task Force classification II-3).

Setting: University-affiliated hospital.

Patients: Included in the study were 184 EP patients treated with MTX between January 2009 and December 2016.

Interventions: Single-dose MTX treatment (50 mg/m²).

Measurements and main results: The patients were treated with repeated doses of MTX every 7 days, if necessary, according to Stovall's protocol, or with laparoscopic surgery in cases of tubal rupture. The success of a single-dose of MTX according to the alternative measure was defined as a >50% decrease in the β-hCG level between days 1 and 7 in clinically stable patients. The sensitivity, specificity, false-negative rate, false-positive rate, and attributable risk of this new monitoring measure were calculated and compared with the traditional regimen. The new protocol had a sensitivity and specificity of 100% and 88.7%, respectively, for predicting a required second dose in patients whose day 1 β-hCG levels were <2000 mIU/mL. For patients with day 1 β-hCG level ≥2000 mIU/mL, both monitoring regimens had the same efficiency.

Conclusions: The new monitoring model without the day 4 β-hCG measurement may offer both patients and clinicians multiple options to monitor single-dose MTX therapy for selected EP patients, with a comparable clinical efficiency to Stovall's protocol and less expense and follow-up burden to patients.

Keywords: Ectopic pregnancy; Single-dose methotrexate treatment; β-hCG monitoring.