1. Department of Obstetrics, Gynecology, Chungnam National University School of Medicine, Chungnam National University Sejong Hospital, Sejong, Korea
2. Department of Obstetrics, Gynecology, Chungnam National University School of Medicine, Chungnam National University Hospital, Daejeon, Korea
3. Department of Laboratory Medicine, Chungnam National University School of Medicine, Chungnam National University Hospital, Daejeon, Korea