This is a prospective observational study aiming to establish reference values of neurofilaments in late preterm newborns (34-37 weeks of gestation) and to evaluate their early postnatal evolution. Neurofilaments are neuronal proteins released into the blood when nerve cells are damaged. They have emerged as promising biomarkers in neurodegenerative diseases, particularly in spinal muscular atrophy (SMA), where higher levels are associated with disease activity. However, very limited data exist on the normal dynamics of neurofilament levels in preterm infants. In this study, up to 15 preterm newborns hospitalized in the neonatal unit will be enrolled (5 at 34 weeks, 5 at 35 weeks, 5 at 36 weeks of gestation). A maximum of 1 mL of additional blood will be collected only during routine clinically indicated blood draws, at birth, on day 2, and weekly until 37 weeks of gestation. Samples will be analyzed for neurofilament concentrations and compared across gestational ages, over time, and with existing data from term newborns and SMA patients. The expected outcome is to generate normative data on neurofilament levels in late preterm infants, which will help interpret biomarker values in future studies and optimize early diagnosis and treatment strategies for neurodegenerative diseases such as SMA.