1. Department of Obstetrics and Gynecology, Shandong Provincial Hospital, Shandong University, Jinan, China
2. Medical Integration and Practice Center, Shandong University, Jinan, China
3. Taian City Central Hospital, Taian, China
4. Affiliated Hospital of Jining Medical University, Jining, China
5. Affiliated Hospital of Qingdao University, Qingdao, China
6. Weihai Municipal Hospital, Weihai, China
7. Qilu Hospital of Shandong University, Jinan, China
8. Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China