1. Integrated Research Center for Fetal Medicine, Department of Gynecology and Obstetrics Johns Hopkins University School of Medicine Baltimore MD USA
2. Department of Obstetrics and Gynecology, CHA Bundang Medical Center CHA University School of Medicine Seongnam Korea
3. Division of Neonatology, Department of Pediatrics Johns Hopkins University School of Medicine Baltimore MD USA
4. Department of Neurology Johns Hopkins University School of Medicine Baltimore MD USA