1. Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Japan
2. Department of Neonatology, Kanagawa Children’s Medical Center, Yokohama, Japan
3. Department of Neonatology, Toho University Omori Medical Center, Tokyo, Japan
4. Department of Pediatrics, International University of Health and Welfare Hospital, Nasushiobara, Japan
5. Department of Neonatology, Japanese Red Cross Narita Hospital, Narita, Japan
6. Department of Pediatrics, Gunma University School of Medicine, Maebashi, Japan
7. Department of Pediatrics, Kumamoto University School of Medicine, Kumamoto, Japan
8. Department of Neonatology, Japanese Red Cross Kyoto Daiichi Hospital, Kyoto, Japan
9. Department of Pediatrics, Sapporo Medical University School of Medicine, Sapporo, Japan