1. Department of Gynecology, Hengshui People's Hospital, Hengshui, Hebei 053000, P.R. China
2. Department of Gynecology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050000, P.R. China
3. Department of Gynecology, Chinese Medicine Hospital of Hebei, Shijiazhuang, Hebei 050000, P.R. China
4. Department of Gynecology, The Fourth Hospital of Shijiazhuang, Shijiazhuang, Hebei 050000, P.R. China