1. Department of Obstetrics and Gynecology, Juntendo University Faculty of Medicine
2. Department of Obstetrics and Gynecology, Aichi Medical University School of Medicine
3. Department of Obstetrics and Gynecology, Ehime University School of Medicine
4. Department of Obstetrics, Osaka City General Hospital
5. Perinatal Center, Divisions of Maternal and Fetal Medicine, Saitama Medical Center, Jichi Medical University
6. Department of Obstetrics and Gynecology, Jichi Medical University School of Medicine
7. Department of Obstetrics and Gynecology, Showa University School of Medicine
8. Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine
9. Department of Obstetrics, Hokkaido University Graduate School of Medicine
10. Department of Obstetrics and Gynecology, St. Barnabas’ Hospital
11. Department of Obstetrics and Gynecology, Hirosaki University Graduate School of Medicine
12. Department of Obstetrics and Gynecology, Tokyo Medical University
13. Division of Public Health, Hygiene and Epidemiology, Tohoku Medical and Pharmaceutical University Faculty of Medicine
14. Department of Obstetrics and Gynecology, Tokyo Women’s Medical University
15. Department of Obstetrics and Gynecology, Palmore Hospital
16. Department of Endocrinology and Hypertension, Tokyo Women’s Medical University
17. Department of Obstetrics and Gynecology, University of Toyama
18. Department of Obstetrics and Gynecology, Saitama Medical University