We measured Protein S-100 serum levels in 66 healthy newborns during the first week of life and in 7 newborns with perinatal acidosis. Normal values (n = 66) constantly ranged between 0.66 and 3.33 microg/l (2.5 and 97.5 percentiles) during the evaluation period.
Conclusions: Newborns with signs of hypoxic-ischaemic encephalopathy (HIE) after perinatal acidosis showed elevated Protein S-100 serum levels, whereas newborns without these signs had normal concentrations. S-100 might thus be a marker of central nervous system damage in newborns. Key words: Asphyxia, brain damage, neonate