*Corresponding Author
Professor Yuanguang Meng, MD, PhD.
Department of Obstetrics and Gynaecology, the Seventh Medical Center of
Chinese PLA General Hospital, Beijing, China
E-mail:meng6512@vip.sina.com
Wensheng Fan, MD.
Department of Obstetrics and Gynaecology, the Seventh Medical Center of
Chinese PLA General Hospital, Beijing, China
E-mail: fanws99@163.com
Running title Survival of four different RH approaches