1. West China Second University Hospital, Sichuan University; Department of Obstetrics and Gynecology; No. 20, 3rd Section of Ren Min Nan Road Chengdu Sichuan China 610041
2. West China Hospital, Sichuan University; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
3. West China Hospital, Sichuan University; West China School of Medicine; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041