1. Department of Obstetrics and Gynecology, Severance Hospital, CHA University School of Medicine, Seoul, Korea.
2. Institute of Women's Life Medical Science, CHA University School of Medicine, Seoul, Korea.
3. Fertility Center of CHA Gangnam Medical Center, CHA University School of Medicine, Seoul, Korea.
4. Department of Obstetrics and Gynecology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.