1. Dept of Obstetrics and Gynecology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, P.R.C
2. Dept of Orthopedics, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, P.R.C
3. Dept of Reproductive Medicine Center, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, P.R.C