1. Center for Maternal, Fetal and Neonatal Medicine, Saitama Medical Center Saitama Medical University Saitama Japan
2. Asahi General Hospital Chiba Japan
3. Education Committee of the Japan Association of Obstetricians and Gynecologists (JAOG) Tokyo Japan
4. Department of Obstetrics and Gynecology Showa University School of Medicine Tokyo Japan
5. Medical Safety and Education Committee of the Japan Association of Obstetricians and Gynecologists (JAOG) Tokyo Japan
6. Department of Obstetrics and Gynecology Nara Medical University Kashihara Japan
7. Department of Obstetrics and Gynecology, Saitama Medical Center Saitama Medical University Saitama Japan