1. 2nd Neonatal Intensive Care Unit and Neonatology Department, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
2. Neonatal Intensive Care Unit, School of Medicine, University of Ioannina, Ioannina, Greece
3. Department of Pathology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece