1. Department of Obstetrics and Gynecology, Showa University School of Medicine
2. Department of Obstetrics and Gynecology, University of Tokyo
3. Department of Obstetrics and Gynecology, Toyama Prefectural Central Hospital
4. Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine
5. Department of Gynecology, Juntendo Tokyo Koto Geriatric Medical Center
6. Department of Gynecology, Medical Topia Soka Hospital
7. Department of Obstetrics and Gynecology, Tokyo Medical University