Dydrogesterone and LNG-IUS for preventing postoperative recurrence after hysteroscopic surgery in patients with endometrial polyps and simple endometrial hyperplasia: a retrospective cohort study

Abstract Background Endometrial polyps (EPs) and non-atypical endometrial hyperplasia (EH) frequently cause abnormal uterine bleeding in reproductive-aged women. While hysteroscopy resects macroscopic lesions, postoperative recurrence is prevalent; progestogen therapy may mitigate recurrence. This study compared efficacy and safety of postoperative dydrogesterone, LNG-IUS and observation alone. Methods A retrospective cohort study of 236 patients (18–46 years, Wuxi Eighth People’s Hospital, 2022.01–2025.02) with pathologically confirmed isolated EP, isolated simple EH or mixed lesions was conducted. Patients with preoperative hormone exposure within 3 months and concurrent AUB-related uterine/cervical disorders were excluded. Patients were grouped into observation ( n = 83), oral dydrogesterone (10 mg twice daily, days 10–23 of each cycle for 3 cycles, n = 128) and LNG-IUS ( n = 25). The primary endpoint was histologically confirmed recurrence at 6 and 12 months; secondary endpoints were symptom relief and adverse events. Multivariate logistic regression was used to identify independent predictors of recurrence. Results Baseline BMI differed across groups ( P = 0.044, with the highest in LNG-IUS group). The 12-month symptomatic improvement rate was 87.9% (observation), 96.8% (dydrogesterone) and 96.0% (LNG-IUS, P = 0.030). Six‑month recurrence rates were 12.0%, 1.6%, 4.0% ( P = 0.005); 12‑month recurrence rates were 22.9%, 9.4%, 4.0% ( P = 0.007). For mixed lesions, the 12‑month recurrence rate was 40.0%, 11.1%, 0% ( P = 0.019) in the observation, dydrogesterone, and LNG-IUS groups, respectively. Dydrogesterone was independently associated with lower recurrence (OR = 0.114, 95%CI 0.024–0.536, P = 0.006), though this estimate should be interpreted cautiously due to the small sample size. Higher BMI was a significant predictor of increased recurrence (OR = 1.206, 95%CI 1.016–1.432, P = 0.033). Conclusions Postoperative dydrogesterone effectively reduces 12‑month recurrence and is well tolerated for reproductive-aged patients. Mixed histology and higher BMI identify high-risk candidates for progestogen prophylaxis. LNG-IUS showed a descriptively lower recurrence rate, but the small sample size ( n = 25) precludes definitive conclusions, and these findings should be considered exploratory.