Managing suboptimal β-hCG response after methotrexate for tubal ectopic pregnancy: outcomes of delaying second intervention to day 10.

OBJECTIVE

To evaluate outcomes of delaying intervention until Day 10 in patients with tubal ectopic pregnancy (EP) showing < 15% β-hCG decline between Days 4-7 after single-dose methotrexate (MTX).

METHODS

This retrospective cohort included patients treated with single-dose MTX for tubal EP (2014-2022). Those without ≥ 15% β-hCG decline by Day 7 were observed until Day 10 before further treatment. . The primary outcome was resolution with a single MTX dose, without additional medical or surgical intervention. Secondary outcomes were associations of β-hCG values and percentage changes with treatment success, analyzed using ROC curves.

RESULTS

Among 340 women, overall success after one MTX dose was 84.4%. Of 49 patients who did not achieve the standard ≥ 15% decline in β-hCG between Days 4 and 7 and were observed until Day 10, 73.5% resolved without additional intervention. Absolute β-hCG levels were significantly lower between the groups at admission (978.4 IU/L vs. 2607.0 IU/L, p < 0.001), 24 h (1007.0 IU/L vs. 2753.0 IU/L, p < 0.001), Day 4 (1080.3 IU/L vs. 3979.0 IU/L, p < 0.001), and Day 7 (837.0 IU/L vs. 2855.5 IU/L, p < 0.001). ROC analysis identified Day 7 β-hCG as the strongest predictor of treatment failure, with an area under the curve (AUC) of 0.876 and an optimal cutoff of 4947.5 IU/L.

CONCLUSIONS

Observation until Day 10 in clinically stable patients with suboptimal β-hCG decline between Days 4 and 7 may safely reduce unnecessary interventions. Absolute Day 7 β-hCG levels provide a reliable predictive tool for guiding clinical decisions. Prospective studies are warranted to validate these findings.