1. West China Second University Hospital; Department of Gynecology and Obstetrics; No. 20, Ren Min Lan Lu Chengdu Sichuan China 610041
2. The Second West China Hospital, Sichuan University; Gynaecology and Obstetrics; Renminnan Road Chengdu Sichuan China 610041
3. West China Secondary Hospital, Sichuan University; Gynecology and Obstetrics; No. 20 Ren Min Nan Road Chengdu Sichuan China 610041
4. West China Secondary Hospital, Sichuan University; Gynaecology and Obstetrics; No. 20, Ren Ming Nan Lu Chengdu Sichuan China 610041