1. Department of Obstetrics and Gynecology The Second Affiliated Hospital of Soochow University Suzhou China
2. Department of Obstetrics and Gynecology Affiliated Hospital of Jiangsu University Zhenjiang China
3. Department of Pathology Affiliated Hospital of Jiangsu University Zhenjiang China
4. Department of Obstetrics and Gynecology First Maternal and Infant Hospital of Tongji University Shanghai China
5. Department of Obstetrics and Gynecology Jurong People's Hospital Jurong China