1. Department of Nursing, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, P.R. China
2. Department of Nutrition, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, P.R. China
3. Department of Gynecology, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, P.R. China