1. Department of Pediatric Surgery; Osaka University Graduate School of Medicine; Suita Japan
2. Department of Public Health, Faculty of Medicine; Osaka City University; Osaka Japan
3. Center for Maternal-Neonatal Care; Nagoya University Hospital; Nagoya Japan
4. Department of Pediatric Surgery; Shizuoka Children's Hospital; Shizuoka Japan
5. Department of Pediatric Surgery; Hyogo Children's Hospital; Kobe Japan
6. Department of Pediatric Surgery; Kanagawa Children's Hospital; Yokohama Japan
7. Department of Neonatology; Osaka Medical Center and Research Institute for Maternal and Child Health; Izumi Japan
8. Division of Neonatology; National Center for Child Health and Development; Tokyo Japan
9. Department of Pediatric Surgery; Nihon University School of Medicine; Tokyo Japan
10. Department of Pediatrics; Hyogo College of Medicine; Nishinomiya Japan
11. Department of Pediatric Surgery; Kyushu University; Fukuoka Japan