Introduction/Background Due to generalization of hysteroscopy, the diagnosis of Atypical hyperplasia of the endometrium in young patients with a fertility preservation wich is a delicate situation for the clinitian and for the patient. We aim to assess the endometrial response rates to treatment with the levonorgestrel intrauterine device (LNG-IUD) in in young women with atypical hyperplasia/endometrial intraepithelial neoplasia endometrial carcinoma who wished to preserve their fertility.

Methodology A prospective monocentric study was conducted from January 2016 to January 2023. Patients under 41 years old with AH were treated with LNG-IUD after complete macroscopic hysteroscopic resection. The histologic change of the endometrial tissue was assessed by both vaginal ultrasound and hysteroscopy with curettage every 3 months. The regression rate was calculated at 6 months of treatment.

Results The study recruited 29 patients. One withdrew because she was pregnant at the time of IUD insertion and 9 did not show during the follow up. Among the 19 patients with sufficient follow up to assess response, 9 had a documented complete response (CR), 5 no response, 4 progressed. Among the patients that had initially a complete response, 2 got pregnant (1 spontaneous miscarriage and 1 premature delivery) and 2 experienced relapse of hyperplasia or cancer after 2 years of follow up.

Conclusion The need for a fertility spearing treatment to AH in young women is real but not so frequent in our daily practice. LNG-IUD treatment in addition to complete macroscopic hysteroscopic resection for AH showed 50% of CR rate at 6 months but relapses were observed after a 2 year follow up.

Disclosures Nothing to disclose