1. Department of Obstetrics and Gynecology Graduate School of Medical Sciences Nagoya City University Nagoya Japan
2. Department of Occupational and Environmental Health Graduate School of Medical Sciences Nagoya City University Nagoya Japan
3. Graduate School of Health and Sports Science Juntendo University Chiba Japan
4. Department of Pediatrics and Neonatology Graduate School of Medical Sciences Nagoya City University Nagoya Japan
5. Department of Health Care Policy and Management Graduate School of Medical Sciences Nagoya City University Nagoya Japan
6. National Center for Child Health and Development Tokyo Japan