1. Department of Obstetrics and Gynecology, Seoul National University Bundang Hospital, Seongnam, Korea.
2. Gynecologic Cancer Center, Department of Obstetrics and Gynecology, Ajou University School of Medicine, Suwon, Korea.
3. Department of Obstetrics and Gynecology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
4. Department of Obstetrics and Gynecology, Korea University College of Medicine, Seoul, Korea.
5. Department of Obstetrics and Gynecology, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun, Korea.
6. Department of Obstetrics and Gynecology, Konkuk University School of Medicine, Seoul, Korea.
7. Department of Obstetrics and Gynecology, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Goyang, Korea.
8. Department of Obstetrics and Gynecology, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
9. Department of Obstetrics and Gynecology, The Catholic University of Korea College of Medicine, Seoul, Korea.
10. Busan Paik Hospital, Paik Institute for Clinical Research, Inje University, Busan, Korea.
11. Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea.
12. Department of Obstetrics and Gynecology, St. Vincent's Hospital, The Catholic University of Korea College of Medicine, Suwon, Korea.
13. Department of Obstetrics and Gynecology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
14. Department of Preventive Medicine, Korea University College of Medicine, Seoul, Korea.
15. Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.