1. Department of Obstetrics and Gynecology Mie University School of Medicine Mie Japan
2. Department of Obstetrics and Gynecology Toho University Omori Medical Center Tokyo Japan
3. Department of Obstetrics and Gynecology St. Marianna University School of Medicine Kanagawa Japan
4. Department of Obstetrics and Gynecology Showa University School of Medicine Tokyo Japan
5. Department of Obstetrics and Gynecology Ishiwata Obstetrics and Gynecology Hospital Ibaraki Japan