1. Neonatal Intensive Care Unit, Hitit University Corum Training and Research Hospital, Corum, Turkey,
2. Division of Neonatology, Department of Pediatrics, Ankara University School of Medicine, Ankara, Turkey,
3. Neonatal Intensive Care Unit, Dr Sami Ulus Maternity and Children Training and Research Hospital, Ankara, Turkey,
4. Division of Neonatology, Department of Pediatrics, Akdeniz University Medical School, Antalya, Turkey,
5. Division of Neonatology, Department of Pediatrics, Gulhane Military School of Medicine, Ankara, Turkey,
6. Neonatal Intensive Care Unit, Konya Training and Research Hospital, Konya, Turkey, and
7. Department of Biostatistics, Ankara University School of Medicine, Ankara, Turkey