Abstract: Objective To study the influencing factors of postoperative pregnancy outcome in patients with moderate to severe ovarian endometriosis treated by ultrasound-guided puncture combined with leuprolide. 
Methods In total, 120 patients with severe ovarian endometriosis admitted to our hospital were enrolled in this study. All patients underwent ultrasound-guided puncture, and 62 patients in the leuprorelin group were supplemented with leuprorelin after operation. The patients were followed up and their pregnancy rate was recorded. The age, duration of infertility, diameter of cyst, single/multiple cyst, endometriosisfertility index(EFI) and preoperative CA125, serum anti-Müllerian hormone(AMH) level, bilateral/unilateral ovarian involvement of patients with successful pregnancy and pregnancy failure were recorded. 
Results At the end of follow-up, all patients were visited, and the follow-up rate was 100%. The pregnancy rate of leuprorelin group was higher than that of non-leuprorelin group(P＜0.05). The recurrence rate of leuprorelin group was lower than that of non-leuprorelin group(P＜0.05). Binary Logistic regression analysis showed that the use of GnRHa after operation, the level of preoperative AMH, bilateral ovarian involvement and the presence of multiple cysts were the independent influencing factors of pregnancy success(P＜0.05). 
Conclusion Ultrasound-guided puncture combined with leuprorelin is effective in the treatment of moderate to severe ovarian endometriosis. The use of GnRHa, preoperative AMH level, bilateral ovarian involvement, and the presence of multiple cysts are the influential factors that affect the success of pregnancy after surgery. 

Key words: endometriosis, ultrasound-guided puncture, leuprorelin