1. Department of Obstetrics and Gynecology, Dongguk University Ilsan Hospital, Goyang, Republic of Korea
2. Dartmouth College, Hanover, NH
3. Department of Obstetrics and Gynecology, National Health Insurance Service Ilsan Hospital, Goyang, Republic of Korea
4. Department of Obstetrics and Gynecology, Institute of Women’s Life Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea
5. Department of Obstetrics and Gynecology, CHA Ilsan Medical Center, CHA University, Goyang, Republic of Korea.