1. Peking Union Medical College Hospital
2. Tsinghua University
3. Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing
4. Department of Obstetrics and Gynaecology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, National Clinical Research Center for Obstetric & Gynecologic Diseases