The role of mifepristone in managing myoma: a systematic review and meta-analysis of uterine parameters

BACKGROUND: Mifepristone has demonstrated favorable effects in managing uterine myomas, particularly for patients aiming to preserve fertility. This study evaluates the effect of Mifepristone on uterine parameters, including uterine volume and endometrial thickness, across different dosages. METHODS: A systematic review and meta-analysis were conducted by searching PubMed, Web of Science, Scopus, Embase, Cochrane Library, and clinical trial registries up to November 30, 2024. Eligible studies were randomized controlled trials (RCTs) comparing Mifepristone with placebo, other drugs, or different Mifepristone dosages in patients with uterine myoma. The primary outcomes were changes in uterine volume and endometrial thickness. Secondary outcomes included symptom relief, such as dyspareunia. Data were pooled using a random-effects model, and effect sizes were expressed as standardized mean differences (SMD) or relative risks (RR) with 95% confidence intervals (CI). RESULTS: Fourteen RCTs involving a total of 1260 patients were included. Higher doses of Mifepristone (10 mg daily) compared to lower doses (5 mg daily) were associated with greater, albeit non-significant, reductions in uterine volume (SMD: -0.08, 95% CI: -0.25 to 0.09, p = 0.35) and a non-significant increase in endometrial thickness (SMD: 0.22, 95% CI: -0.23 to 0.66, p = 0.34). The 10 mg dose was significantly more effective in resolving dyspareunia (RR: 1.87, 95% CI: 1.59 to 2.20, p < 0.01). CONCLUSION: Our analysis indicated that Mifepristone was associated with a non-significant reduction in uterine volume among patients with uterine myoma. However, higher daily doses (10 mg) demonstrated greater clinical benefits in relieving dyspareunia, despite minimal changes in uterine size. These findings suggest that higher doses (10 mg daily) may be a consideration for symptom relief, particularly for dyspareunia, despite minimal changes in uterine size. This suggestion is preliminary, given the non-significant primary outcomes and low certainty of evidence for key comparisons.