1. Department of Obstetrics and Gynecology, Toho University Ohashi Medical Center, Tokyo, Japan.
2. Department of Obstetrics and Gynecology, Tokai University School of Medicine, Isehara, Japan.
3. Department of Obstetrics and Gynecology, Kyorin University Faculty of Medicine, Tokyo, Japan.
4. Department of Obstetrics and Gynecology, Faculty of Medicine, Juntendo University, Tokyo, Japan.
5. Department of Obstetrics and Gynecology, Tokyo Women’s Medical University, Tokyo, Japan.
6. Division of Gynecology, Shizuoka Cancer Center, Shizuoka, Japan.
7. Department of Obstetrics and Gynecology, Iwate Medical University, Iwate, Japan.
8. Department of Obstetrics and Gynecology, Yamagata University Faculty of Medicine, Yamagata, Japan.