1. Department of Obstetrics and Gynecology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea.
2. Department of Pediatrics, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea.
3. Department of Radiology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea.
4. Department of Surgery, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea.
5. Division of Maternal and Fetal Medicine, Department of Obstetrics and Gynecology, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Korea.