1. Department of Gynaecology, The First Affiliated Hospital of XinJiang Medical University, Urumqi City, P.R. China.
2. Department of Gynaecology, The First People's Hospital of Urumqi, Urumqi City, P.R. China.
3. Department of Obstetrics and Gynecology, Dushanzi People's Hospital, Karamay City, P.R. China.