1. Division of Neonatology, Center for Maternal‐Fetal, Neonatal and Reproductive Medicine, National Center for Child Health and Development Setagaya‐ku Japan
2. Division of Biostatistics, Clinical Research Center National Center for Child Health and Development Setagaya‐ku Japan
3. Department of Gastrointestinal and Pediatric Surgery Mie University Graduate School of Medicine Tsu Japan
4. Department of Pediatric Surgery Kobe Children's Hospital Kobe Japan
5. Department of Pediatric General and Urogenital Surgery Juntendo University School of Medicine Tokyo Japan
6. Department of Pediatric Surgery, Graduate School of Medical Science Kyoto Prefectural University of Medicine Kyoto Japan
7. Department of Neonatology, Kanagawa Children's Medical Center Yokohama Japan
8. Department of Pediatrics Kindai University, Faculty of Medicine Osaka‐Sayama Japan
9. Department of Pediatric Surgery Juntendo University Urayasu Hospital Urayasu Japan
10. Department of Pediatric Surgery Shizuoka Children's Hospital Shizuoka Japan
11. Department of Pediatric Surgery, Faculty of Medicine University of Tsukuba Tsukuba Japan
12. Department of Pediatric Surgery, Graduate School of Medicine Chiba University Chiba Japan
13. Department of Pediatric Surgery Osaka University Graduate School of Medicine Suita Japan
14. Center for Maternal‐Neonatal Care, Nagoya University Hospital Nagoya Japan
15. Department of Pediatric Surgery, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
16. Fukuoka College of Health Sciences Fukuoka Japan
17. Department of Pediatric Surgery Osaka Women's and Children's Hospital Izumi Japan