1 Fetal and Neonatal Department, Anna Meyer Children Hospital, University of Firenze, Viale Pieraccini 24, 50139 Florence, Italy. Electronic address: maria.pignotti@meyer.it.
2 Department of Medical, Surgical and Neurological Sciences, University of Siena, Via delle Scotte, 53100 Siena, Italy.
3 Department SAIMLAL, Sapienza University of Rome, Viale Regina Elena 336, 00185 Rome, Italy.