Metformin Plus Megestrol Acetate As a Fertility-sparing Treatment in Patients with Atypical Endometrial Hyperplasia

Inclusion Criteria: 1. 18-45 years old; 2. pathologically diagnosed with AEH for the first time; 3. desire to preserve their fertility; 4. no signs of suspicious myometrial invasion or extrauterine metastasis by enhanced magnetic resonance imaging (MRI), enhanced computed tomography (CT) or transvaginal ultrasonography (TVUS); 5. no contraindication for metformin, megestrol acetate or pregnancy; 6. no hormone or metformin treatment within 6 months before entering the trial; 7. not pregnant when participating in the trial; 8. willing to follow the trial arrangement after being fully informed of all the risks and inconveniences caused by the trial. Exclusion Criteria: Patients who had one or more of the following conditions: 1. allergy history or contraindications for megestrol acetate or metformin; 2. pregnant when initiating the study; 3. alcoholism, severe infection, severe chronical diseases (dysfunction of heart, liver, lung or kidney); 4. high risk of thrombosis; 5. recurrent AEH; 6. endometrial cancer; 7. other malignancy history.