1. Department of Gynecology, Tohoku University Hospital, Miyagi, Japan.
2. Department of Obstetrics and Gynecology, Tokai University School of Medicine, Kanagawa, Japan.
3. Department of Obstetrics and Gynecology, Faculty of Medicine, Yamagata University, Yamagata, Japan.
4. Department of Obstetrics and Gynecology, Kyorin University Faculty of Medicine, Tokyo, Japan.
5. Department of Obstetrics and Gynecology, Tokyo Women's Medical University, Tokyo, Japan.
6. Department of Gynecology, Otaru General Hospital, Hokkaido, Japan.
7. Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
8. Department of Gynecology, Shizuoka Cancer Center, Shizuoka, Japan.
9. Department of Obstetrics and Gynecology, Kindai University Faculty of Medicine, Osaka, Japan.
10. Department of Obstetrics and Gynecology, Hirosaki University Graduate School of Medicine, Aomori, Japan.
11. Department of Obstetrics and Gynecology, Nihon University School of Medicine, Tokyo, Japan.
12. Department of Obstetrics and Gynecology, Shimane University School of Medicine, Shimane, Japan.
13. Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan.
14. Department of Obstetrics and Gynecology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.