1. Department of Gynecology, People's Hospital of Qingdao West Coast New Area, Qingdao, Shandong 266400, P.R. China
2. Department of Surgery, People's Hospital of Qingdao West Coast New Area, Qingdao, Shandong 266400, P.R. China
3. Department of Outpatient Department, People's Hospital of Qingdao West Coast New Area, Qingdao, Shandong 266400, P.R. China