Assessing ovarian stimulation with letrozole and levonorgestrel intrauterine system after combined fertility-sparing approach for atypical endometrial lesions: a retrospective case-control study.

Research Question: Is ovarian stimulation with levonorgestrel intrauterine system (LNG-IUS) in situ and co-treatment with letrozole safe and effective in patients undergoing fertility-sparing combined treatment for atypical endometrial hyperplasia (AEH) or early endometrial cancer limited to the endometrium?

Design: Retrospective case-control study recruiting women who had undergone fertility-sparing 'combined' treatment and ovarian stimulation with letrozole and LNG-IUS in situ. The 'three steps' hysteroscopic technique was used. Once complete response was achieved, the ovaries were stimulated, and mature oocytes cryopreserved.