Dydrogesterone for preventing endometrial polyp recurrence after transcervical resection of polyps: protocol for a multicentre randomised controlled trial in China.

introductionTo assess the effects of oral dydrogesterone on the recurrence rate of endometrial polyps (EPs) and abnormal uterine bleeding (AUB) symptoms after transcervical resection of polyps (TCRP). METHODS AND ANALYSIS: A randomised, parallel, open-label, multicentre study will be conducted across 12 hospitals in China, including general and women's specialty hospitals. In this study, we will recruit female patients aged 18-46 years diagnosed with EPs using transvaginal ultrasonography during two menstrual cycles. Eligible participants who have not received other oestrogen or progesterone treatments will be randomly assigned in a 1:1 ratio to either an intervention or control group. All participants will undergo TCRP, with the time between randomisation and surgery not exceeding 14 days. The intervention group will receive oral dydrogesterone for three menstrual cycles, whereas the control group will receive no hormonal treatment. The primary outcome is the recurrence rate of EPs, which will be evaluated using follow-up transvaginal ultrasonography at 1, 3, 6, 12, 18 and 24 months postsurgery. Secondary outcomes include assessment of AUB and menstrual status. For statistical analyses, a multivariate regression will be used to adjust for confounding factors. ETHICS AND DISSEMINATION: This study protocol adheres to the Declaration of Helsinki and has been approved by the Women's Hospital, School of Medicine, Zhejiang University (IRB-20240077-R). All participants in the trial will provide written informed consent. The study findings will be published in peer-reviewed journals and presented at academic conferences. TRIAL REGISTRATION NUMBER: ChiCTR2400083097.