Follow-up after hospital discharge All newborns will be followed-up at the Follow-Up Ambulatory until the first year of life, during which the laboratorial follow-up will be conducted (Hematocrit/Coombs) as well as the complete physical and neurological examination. The Bayley method will be used for neurological evaluation, to be performed by a trained professional at the end of the first year of life. Every fact related to the clinical evolution during the first year of life will be recorded: the presence of cholestasis, nutritional situation (evaluation) through z-score at the time of hospital discharge, by the 6th month and at the end of the first year, regarding weight, height and head perimeter, using NCHS as standard; hospital admittance for blood transfusion or other treatments, presence of infection that might be related to the use of blood derivates (hepatitis B and C , cytomegalovirus).