1. Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, 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, Tokyo Women's Medical University, Tokyo, Japan.
5. Department of Obstetrics and Gynecology, Kyorin University Faculty of Medicine, Tokyo, Japan.
6. Department of Gynecology, Otaru General Hospital, Hokkaido, Japan.
7. Department of Obstetrics and Gynecology, Faculty of Medicine, Kagoshima University, Kagoshima, Japan.
8. Department of Gynecology, Miyagi Cancer Center, Miyagi, Japan.
9. Department of Obstetrics and Gynecology, Dokkyo Medical University, Tochigi, Japan.
10. Department of Obstetrics and Gynecology, Jichi Medical University, Tochigi, Japan.
11. Department of Obstetrics and Gynecology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.