1. Department of Obstetrics & Gynecology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
2. Department of Obstetrics & Gynecology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
3. Department of Obstetrics & Gynecology, Tufts University School of Medicine, Boston, MA, USA
4. Department of Obstetrics and Gynecology, Hallym University Kangdong Sacred Heart Hospital, Seoul, Republic of Korea