1. Department of Obstetrics and Gynecology, Gangnam CHA Hospital, CHA University, Seoul, Korea.
2. Department of Radiology, Gumi CHA Hospital, CHA University, Gumi, Korea.
3. Department of Pathology, Gumi CHA Hospital, CHA University, Gumi, Korea.
4. Department of Obstetrics and Gynecology, Gumi CHA Hospital, CHA University, Gumi, Korea.