1. Department of Obstetrics and Gynecology Jichi Medical University Tochigi Japan
2. Department of Obstetrics and Gynecology Koga Red Cross Hospital Koga Ibaraki Japan
3. Medical Examination Center Ibaraki Western Medical Center Chikusei Ibaraki Japan
4. Department of Pediatrics Jichi Medical University Tochigi Japan
5. Department of Pediatrics International University of Health and Welfare Hospital Nasushiobara Tochigi Japan