1. Department of Obstetrics and Gynecology Jichi Medical University Tochigi Japan
2. Department of Obstetrics and Gynecology Koga Red Cross Hospital Shimoyama, Koga Ibaraki Japan
3. Department of Pediatrics Division of Cardiology The Children's Hospital of Philadelphia Philadelphia PA USA
4. Athinoula A. Martinos Center for Biomedical Imaging Massachusetts General Hospital Charlestown MA USA