1. Department of Obstetrics and Gynecology Tokyo Medical University Shinjuku Japan
2. Faculty of Medicine University Hospital, Department of Obstetrics and Gynecology The University of Tokyo Tokyo Japan
3. Department of Obstetrics and Gynecology Gunma University Graduate School of Medicine Maebashi Japan
4. Department of Obstetrics and Gynecology Yamaguchi University Hospital Ube Japan
5. Department of Gynecology Kurashiki Heisei Hospital Kurashiki Japan
6. Department of Obstetrics and Gynecology University of Yamanashi Hospital Yamanashi Japan
7. Department of Obstetrics and Gynecology Saitama Medical Center, Saitama Medical University Kawagoe Japan