1. Department of Neonatology; Gifu Prefectural General Medical Center; Gifu Japan
2. Department of Pediatrics; Graduate School of Medicine; Gifu University; Gifu Japan
3. Perinatal Medical Center; Kagoshima City Hospital; Kagoshima Japan
4. Department of Neonatology; Fukuda Hospital; Kumamoto Japan
5. Department of Obstetrics and Gynecology; University of Toyama; Toyama Japan
6. Department of Obstetrics and Gynecology; Asahi Central Hospital; Chiba Japan
7. Department of Neonatology; Funabashi Central Hospital; Chiba Japan
8. Perinatal Center; Imakiire General Hospital; Kagoshima Japan