1. Department of Women Health and Territorial Medicine, University of Rome “La Sapienza”, 00185 Rome, Italy
2. Department of Pediatrics, University of Naples “Federico II”, 80131 Naples, Italy
3. Neonatal Unit, “V. Monaldi” Hospital, 80131 Naples, Italy
4. A. Cardarelli Hospital, 80131 Naples, Italy
5. Neonatal Unit, “Fatebenefratelli” Hospital, 80123 Naples, Italy
6. Neonatal Unit, “Villa Betania” Evangelical Hospital, 80100 Naples, Italy