1. Department of Obstetrics and Gynecology Kansai Rosai Hospital Amagasaki Japan
2. Department of Obstetrics and Gynecology Osaka Police Hospital Osaka Japan
3. Department of Obstetrics and Gynecology Osaka University Graduate School of Medicine Suita Japan
4. Department of Obstetrics and Gynecology Iwate Medical University Shiwa Japan
5. Department of Obstetrics and Gynecology Kurume University School of Medicine Kurume Japan
6. Department of Obstetrics and Gynecology Niigata University Graduate School of Medical and Dental Sciences Niigata Japan
7. Department of Obstetrics and Gynecology Niigata Cancer Center Niigata Japan
8. Department of Obstetrics and Gynecology Tottori University School of Medicine Yonago Japan
9. Department of Obstetrics and Gynecology Jichi Medical University Shimotsuke Japan
10. Department of Obstetrics and Gynecology The Jikei University School of Medicine Tokyo Japan
11. Department of Obstetrics and Gynecology The Jikei University Kashiwa Hospital Kashiwa Japan
12. Department of Medical Innovation Data Coordinating Center Osaka University Hospital Suita Japan