1. Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea
2. College of Life Sciences and Biotechnology, Korea University, Seoul, Korea
3. Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
4. Department of Clinical Laboratory Science, College of Health Sciences, Korea University, Seoul, Korea
5. Department of Obstetrics and Gynecology, Yonsei University Health System, Seoul, Korea