1. Medical Research Center, Binzhou Medical University Hospital, Binzhou, P.R. China
2. Department of Gynecology, Binzhou Medical University Hospital, Binzhou, P.R. China
3. The First School of Clinical Medicine of Binzhou Medical University, Binzhou Medical University Hospital, Binzhou, P.R. China
4. Medical Integration and Practice Center, Shandong University, Jinan, P.R. China
5. Qilu Hospital of Shandong University, Jinan, P.R. China