[Composition of the cerebrospinal fluid in the premature newborn infant].

The composition of the spinal fluid was determined in 54 healthy premature infants in the first week of life. The infants were divided into three groups according to their gestational age; the results in each group, submitted to variance analysis, indicated similar values. The results in these premature infants were then compared with those in 79 normal full-term infants. The spinal fluid of the pre-term children showed higher bilirubin concentrations, more hemoglobin and higher levels of protein, indicating a greater permeability and immaturity of the blood-brain barrier. There were more erythrocytes in the premature infants, while the number of leukocytes and their differential count were similar in both groups; the only difference was the number of eosinophils, which were absent in the premature infants.