Dydrogesterone versus levonorgestrel-releasing intrauterine system for abnormal uterine bleeding: a propensity score-matched analysis of long-term efficacy and recurrence

To compare dydrogesterone versus levonorgestrel-releasing intrauterine system (LNG-IUS) for abnormal uterine bleeding (AUB) management with long-term follow-up and etiology-stratified analysis. This single-center retrospective cohort study analyzed reproductive-aged women with International Federation of Gynecology and Obstetrics (FIGO)-classified AUB receiving dydrogesterone (n = 131) or LNG-IUS (n = 118). Propensity score matching balanced baseline covariates between groups (n = 104 pairs). Primary outcomes were bleeding control rates (composite: hemoglobin increase ≥ 1.5 g/dL, ≥ 50% Pictorial Blood Loss Assessment Chart [PBAC] reduction, no rescue interventions) at 3 and 12 months. Secondary outcomes included 24-month recurrence and adverse events (AEs). LNG-IUS demonstrated superior 3-month bleeding control versus dydrogesterone (82.7% vs. 65.4%; relative risk [RR] 1.26, 95% confidence interval [CI] 1.08–1.48; p = 0.002). At 12 months, bleeding control rates were comparable between groups (78.8% vs. 72.1%; RR 1.09, 95% CI 0.96–1.24; p = 0.17). LNG-IUS significantly reduced 24-month recurrence risk (hazard ratio [HR] 0.48, 95% CI 0.32–0.72; p < 0.001), particularly for structural AUB (HR 0.39, 95% CI 0.24–0.64). Subgroup analysis revealed LNG-IUS superiority in adenomyosis at 12 months (88.2% vs. 60.0%; RR 1.47, 95% CI 1.24–1.74; p < 0.001) but comparable efficacy in nonstructural AUB (76.6% vs. 72.9%; RR 0.95, 95% CI 0.78–1.16; p = 0.63). Dydrogesterone exhibited higher systemic AEs (28.2% vs. 13.6%; p = 0.003), while LNG-IUS had device-related events including expulsion (5.1%). LNG-IUS offers superior short-term bleeding control and sustained long-term recurrence prevention, especially for structural AUB. Dydrogesterone effectively manages nonstructural etiologies but carries higher systemic adverse event rates. Treatment selection should be etiology-guided, balancing immediate symptom control versus recurrence prevention and individualized safety considerations.