Factors associated with hysterectomy after failure of levonorgestrel-releasing intrauterine system treatment in women with abnormal uterine bleeding

Abnormal uterine bleeding (AUB) is a common gynecological condition with a significant impact on women’s quality of life and public health. Although the levonorgestrel-releasing intrauterine system (LNG-IUS) is an effective first-line treatment, a subset of women ultimately require hysterectomy. The demographic, clinical, ultrasonographic, and histopathological factors associated with LNG-IUS treatment failure remain insufficiently understood. This retrospective descriptive study included 233 women diagnosed with AUB who underwent LNG-IUS (Mirena®) insertion between November 2019 and December 2022 at a tertiary referral center. Patients were divided into two groups according to hysterectomy status during follow-up. Demographic data, PALM–COEIN classification, ultrasonographic findings, and histopathological results were analyzed. Of the 233 women, 60 (25.7%) underwent hysterectomy due to treatment-resistant bleeding, while 173 (74.2%) were managed successfully without surgery. Women in the hysterectomy group were significantly older than those in the non-hysterectomy group (median age 45.35 vs. 41.76 years, p = 0.001). Body mass index and parity did not differ significantly between groups. Structural uterine pathology was present in 92% of patients who required hysterectomy. Leiomyoma was the most common histopathological finding (38.3%), followed by adenomyosis (21.7%). Combined pathologies, including adenomyosis with leiomyoma or endometrial polyps, were also frequent. By contrast, most women in the non-hysterectomy group had no identifiable structural uterine abnormalities. The effectiveness of the LNG-IUS in AUB management is strongly influenced by underlying structural uterine pathology. Leiomyoma and adenomyosis, particularly when coexisting, are major predictors of treatment failure and subsequent hysterectomy. Careful pre-treatment evaluation and individualized counseling are essential to optimize patient selection and treatment outcomes.