1. Department of Gynecology and Obstetrics, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, 2800 Gongwei Road, Pudong, Shanghai 201399, China
2. Departement of Gynecology and Obstetrics, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), 183 Xinqiao Street, Shapingba, Chongqing 400037, China