1. Neonatal Intensive Care Unit, Children's Hospital of Brescia, Brescia, Italy;
2. Neonatal Intensive Care Unit, Azienda Ospedaliera and University of Cagliari, Cagliari, Italy;
3. Blood Bank Service, Gaslini Children's Hospital, Genova, Italy; and
4. Neonatal Intensive Care Unit, Azienda Ospedaliera, Perugia, Italy