1. Neonatal Intensive Care Unit, Center for Neonatology, Pediatric Clinic, University Clinical Centre Kragujevac , Kragujevac , Serbia
2. Department of Alloartoplastic Surgery, Clinic for Orthopedics and Traumatology, University Clinical Center Kragujevac , 34000 Kragujevac , Serbia
3. Department of Surgery, Faculty of Medical Sciences, University of Kragujevac , Svetozara Markovica 69 , 34000 Kragujevac , Serbia
4. Department of Medical Statistics and Informatics, Faculty of Medical Sciences, University of Kragujevac , Kragujevac , Serbia
5. Department of Pediatrics, Faculty of Medical Sciences, University of Kragujevac , Kragujevac , Serbia
6. Department of Cardiology, Pediatric Clinic, University Clinical Centre Kragujevac , Kragujevac , Serbia
7. Department of Gastroenterology, Pediatric Clinic, University Clinical Centre Kragujevac , Kragujevac , Serbia
8. Department of Pulmonology, Pediatric Clinic, University Clinical Centre Kragujevac , Kragujevac , Serbia
9. Department of Neonatology, Clinic for Gynecology and Obstetrics, University Clinical Centre Kragujevac , Kragujevac , Serbia