1Department of Pediatric Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
2Department of Pediatric Surgery, Reproductive and Developmental Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
3Department of Pediatric Surgery, Shizuoka Children’s Hospital, Shizuoka, Japan
4Division of Neonatology, Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Japan
5Department of Pediatric Surgery, Osaka University Graduate School of Medicine, Suita, Japan
6Division of Neonatology, National Center for Child Health and Development, Tokyo, Japan
7Department of Pediatric Surgery, Kobe Children’s Hospital, Kobe, Japan
8Department of Pediatric Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
9Department of Pediatric Surgery, Tsukuba University, Tsukuba, Japan
10Department of Pediatric Surgery, Juntendo University Urayasu Hospital, Urayasu, Japan
11Department of Pediatrics, Kindai University, Higashiosaka, Japan
12Department of Neonatology, Kanagawa Children's Medical Center, Yokohama, Japan
13Department of Gastrointestinal and Pediatric Surgery, Mie University Graduate School of Medicine, Tsu, Japan
14Department of Pediatric General and Urogenital Surgery, Juntendo University School of Medicine, Tokyo, Japan
15Department of Preventive Medicine and Public Health, Keio University, Tokyo, Japan
16Department of Pediatric Surgery, Osaka Women’s and Children’s Hospital, Izumi, Japan