1. Department of Obstetrics and Gynecology, Ansan Hospital, Korea University College of Medicine, Ansan 15355, Republic of Korea
2. Department of Obstetrics and Gynecology, Guro Hospital, Korea University College of Medicine, Seoul 02841, Republic of Korea
3. Department of Pathology, Guro Hospital, Korea University College of Medicine, Seoul 02841, Republic of Korea
4. Biomedical Research Institute, Kangwon National University Hospital, Chuncheon 24289, Republic of Korea