Pregnancy Outcomes Following Medical Therapy versus Levonorgestrel-Releasing Intrauterine System for Atypical...

To compare pregnancy outcomes between systemic progestin therapy and levonorgestrel-releasing intrauterine system (LNG-IUS) in patients with atypical endometrial hyperplasia (AEH) desiring fertility preservation.

This single-center retrospective cohort study included AEH patients who underwent fertility-sparing treatment between January 2017 and December 2024. Patients received either systemic progestins (medroxyprogesterone acetate [MPA] 250-600 mg/day, megestrol acetate [MA] 160-320 mg/day, or dydrogesterone 20-40 mg/day) or LNG-IUS. Primary outcomes were clinical pregnancy rate and live birth rate. Secondary outcomes included time to pregnancy (TTP), conception mode, and disease recurrence rate. Propensity score matching (PSM) controlled for confounders including age, body mass index, polycystic ovary syndrome, and infertility duration.

Of 186 patients (121 medical therapy, 65 LNG-IUS), 58 per group were analyzed after PSM. Complete remission rates were 77.6% (45/58) versus 84.5% (49/58) (adjusted OR 1.52, 95% CI 0.71-3.26, p=0.28). Among patients achieving complete remission, clinical pregnancy rates were 51.1% (23/45) versus 67.3% (33/49) (adjusted OR 2.14, 95% CI 1.08-4.25, p=0.029). Live birth rates were 37.8% (17/45) versus 55.1% (27/49) (adjusted OR 2.28, 95% CI 1.13-4.62, p=0.022). Median TTP was 8.5 months (IQR 6-14) versus 6.0 months (IQR 4-10) (HR 1.64, 95% CI 1.12-2.41, p=0.011). Per-protocol analysis yielded consistent results.

LNG-IUS treatment was associated with significantly higher clinical pregnancy rates, live birth rates, and shorter TTP compared to systemic progestin therapy. These findings support LNG-IUS as a preferred fertility-sparing option for AEH patients, particularly when expedited conception is desired. Results should be interpreted considering the retrospective design, heterogeneous dosing, and potential residual confounding.