1. Department of Obstetrics and Gynecology, Nippon Medical School Hospital
2. Department of Obstetrics and Gynecology, Kato Women's Clinic
3. Division of Obstetrics and Gynecology, Graduate School of Medical and Dental Sciences, Niigata University
4. Department of Obstetrics and Gynecology, Graduate School of Medical Science, University of the Ryukyus
5. Department of Obstetrics and Gynecology, Nippon Medical School Musashi Kosugi Hospital
6. Division of Gynecology, Niigata Prefectural Cancer Center Hospital
7. Department of Gynecology, Kanagawa Cancer Center Hospital
8. Department of Obstetrics and Gynecology, Nippon Medical School Chiba Hokusoh Hospital