1. Department of Obstetrics and Gynaecology Jichi Medical University Tochigi Japan
2. Department of Obstetrics and Gynaecology Koga Red Cross Hospital Koga Japan
3. Department of Paediatrics Jichi Medical University Tochigi Japan
4. Athinoula A. Martinos Center for Biomedical Imaging Massachusetts General Hospital, Harvard Medical School Charlestown Massachusetts USA