Ultrasound-derived gestational sac triple product as a predictor of early medical abortion failure with mifepristone-misoprostol regimens: a retrospective cohort study.

Objective: Early medical abortion (EMA) with mifepristone-misoprostol commonly relies on subjective metrics (e.g., last menstrual period-derived gestational age) for failure risk assessment, which may introduce uncertainty. This retrospective study aimed to identify objective predictors of EMA failure and explore the utility of different gestational sac size metrics for clinical risk stratification. Study design: Early pregnancy outpatients who underwent medical abortion with the mifepristone-misoprostol regimen at Karamay Central Hospital (Xinjiang, China) from December 2024 to July 2025 were included in our study. EMA failure was defined as the need for surgical evacuation. Analyses included univariate assessment, logistic regression, and performance evaluation of gestational sac size metrics. Results: After exclusion, 159 women were included in the final analyses. The overall EMA success rate was 89.31% (142/159). Maternal age ≥35 years was associated with higher failure risk (OR = 2.82, 95% CI, 1.01-7.89, Conclusion: Gestational sac size is an important objective indicator for predicting mifepristone-misoprostol EMA failure, and among various gestational sac size metrics, the triple product of diameters demonstrates the highest predictive value.