1. Institute of Women's Life Medical Science, Department of Obstetrics and Gynecology, Yonsei University College of Medicine, Seoul, Korea
2. Department of Obstetrics and Gynecology, Yonsei University Graduate School, Seoul, Korea
3. Department of Pathology, Gangnam Severance Cancer Hospital, Yonsei University College of Medicine, Seoul, Korea
4. Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, Seoul, Korea
5. Department of Obstetrics and Gynecology, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea