1. Department of Obstetrics and Gynecology Nara Medical University Nara Japan
2. Department of Obstetrics and Gynecology Faculty of Medicine, Tottori University Tottori Japan
3. Department of Gynecology Hokkaido University School of Medicine, Hokkaido University Sapporo Hokkaido Japan
4. Department of Obstetrics and Gynecology The Jikei University School of Medicine Tokyo Japan
5. Department of Global Health Promotion Tokyo Medical and Dental University Tokyo Japan
6. Department of Obstetrics and Gynecology Kyorin University School of Medicine Mitaka Japan
7. Department of Obstetrics and Gynecology Nagasaki University Hospital Nagasaki Japan
8. Department of Obstetrics and Gynecology Yokohama Rosai Hospital Yokohama Japan
9. Department of Obstetrics and Gynecology Akita University Hospital Akita Japan
10. Department of Obstetrics and Gynecology School of Medicine, Shinshu University Nagano Japan
11. Department of Obstetrics and Gynecology Kameda Medical Center Chiba Japan
12. Nippon Medical School Tamanagayama Hospital Tokyo Japan
13. Department of Obstetrics and Gynecology Kochi Medical School Nankoku Japan
14. Department of Obstetrics and Gynecology Tokyo Medical University Tokyo Japan
15. Department of Obstetrics and Gynecology Faculty of Life Sciences, Kumamoto University Kumamoto Japan
16. Department of Obstetrics and Gynecology Kaizuka City Hospital Osaka Japan
17. Department of Obstetrics and Gynecology Showa University School of Medicine Tokyo Japan
18. Department of Gynecology and Obstetrics School of Medicine, Kyoto University Graduate Kyoto Japan
19. Department of Obstetrics and Gynecology Japanese Red Cross Yamaguchi Hospital Yamaguchi Japan
20. Department of Obstetrics and Gynecology Faculty of Medicine, Mie University Tsu Mie Japan
21. Department of Obstetrics and Gynecology Tannan Regional Medical Center Fukui Japan
22. Department of Obstetrics and Gynecology Graduate School of Medicine, Okayama University Okayama Japan
23. Department of Obstetrics and Gynecology University of Toyama Toyama Japan
24. Department of Reproductive Medicine Graduate School of Medicine, Chiba University Chiba Japan
25. Department of Obstetrics and Gynecology The University of Tokyo Tokyo Japan
26. Department of Obstetrics and Gynecology Faculty of Medical Sciences, University of Fukui Fukui Japan