1. Fondazione IRCCS Policlinico San Matteo, Neonatal Intesive Care Unit, Pavia, Italy;
2. Fondazione IRCCS Policlinico San Matteo, Pediatric Clinic, IRCCS San Matteo Foundation, Pavia, Italy;
3. Fondazione IRCCS Policlinico San Matteo, Pavia, Italy;
4. Neonatology and Neonatal Intensive Care Unit, S. Anna Hospital, Torino, Italy;
5. Division of Neonatology, Casilino General Hospital, Rome, Italy;
6. Neonatal Intensive Care Unit, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy