[1] Univ Florence, Dept Hlth Sci, Sect Pediat, Florence, Italy
[2] Univ Hosp Padova, Dept Womans & Childs Hlth, Padua, Italy
[3] Univ Florence, Dept Hlth Sci, Florence, Italy
[4] Bambino Gesu Children Hosp IRCCS, Pediat Dis Unit, Piazza St Onofrio 4, I-00165 Rome, Italy
[5] Univ Turin, Dept Publ Hlth & Pediat Sci, Complex Struct Neonatol Unit, Turin, Italy
[6] Univ Bologna, Dept Med & Surg Sci, Alma Mater Studioru, Bologna, Italy
[7] Univ Hosp Infermi, Dept Pediat & Neonatol, Biella, Italy
[8] ASL RM 1, Rome, Italy
[9] Maggiore Hosp, Neonatal Intens Care Unit, Bologna, Italy
[10] Sanofi Pasteur, Med Affairs, Milan, Italy
[11] Univ Hosp Verona, Dept Pediat, Pediat Div, Verona, Italy
[12] NICU Fdn IRCCS Ca Granda Osped Maggiore Policlin, Milan, Italy
[13] Univ Milan, Dept Clin Sci & Community Hlth, Milan, Italy