The aim of this clinical trial is to learn if there is a correlation between the erythrocyte transfusion in the early neonatal period in premature infants and early and late complications of prematurity. The main questions it aims to answer are:
* Do premature infants who receive blood transfusions within their first month of life have a higher risk of early prematurity complications, such as retinopathy of prematurity, necrotising enterocolitis, bronchopulmonary dysplasia, and intraventricular haemorrhage?
* Do premature infants who receive blood transfusions during their first month of life have worse neurological and neurodevelopmental outcomes than those who do not? The first part of the study is retrospective, using data collected from participants' histories. The second part is prospective, evaluating neurological and neurodevelopmental outcomes at the age of six years.