Objective To assess the safety of continuous uterus-preserving in endometrial cancer (EC) and atypical endometrial hyperplasia (AEH) patients who gave birth after fertility-sparing treatment (FST). Design A retrospective study conducted between January 2005 and June 2020. Setting Peking University People’s Hospital, China. Population A total of 212 EC/AEH patients undergoing FST. Methods Patients were stratified as patients with a live-birth (n=73) outcome and those without (n=139). Main Outcomes Measures Risk factors for disease recurrence were analyzed for all patients undergoing FST and postpartum recurrence was analyzed for those with live-birth after FST. Results Live-birth significantly reduced the risk of disease recurrence (HR 0.326, P=0.011), while insulin resistance is an adverse factor (HR 3.216, P=0.014). Exceprt for two patients who underwent hysterectomy, for the 71 patients with uterus-preserving after live-birth, five (7%) patients occurred disease relapse (one EC and four AEH), after a median follow-up of 26 (11, 47.5) months. While there were another eight patients (11.3%) experiencing hyperplasia without atypical (EH). Risk factors for postparturm EC/AEH/EH included irregular menstrual period (75% vs. 36.8%, P=0.028), abnormal echo of ultrasound (53.8% vs. 13.7%, P=0.005) and a thicker endometrium (0.76cm vs. 0.53cm, P=0.003) . While maintenance treatment after birth (38.5% vs. 62.5%, P=0.129) tended to have a protective effect. Conclusions Alough live-birth for EC/AEH patients who underwent FST has benefit on recurrence-free survival, there still exists a postpartum risk of disease recurrence, with irrregular menstruation, thicker endometrium and abnormal ultrasound as risk factors.