1. Department of Gynecology, Dalian Women and Children’s Medical Center (Group), Dalian, China
2. School of Clinical Medicine, Fujian Medical University, Department of General Surgery, Ningde Municipal Hospital, Ningde, China
3. School of Clinical Medicine, Fujian Medical University, Department of Obstetrics and Gynecology, Ningde Municipal Hospital, Ningde, China
4. Department of Obstetrics and Gynecology, Dalian No.3 People’s Hospital, Dalian, China