Background: As suggested by some investigators in the recently published reports, protein C and protein S deficiency may be one of the etiologic factors responsible for the development of the grade IV intraventricular haemorrhage (IVH).Material/Methods: The study population consists of four premature newborns with USG confirmed grade IV IVH. We measured protein C and protein S levels in blood of our patients between the third and the seventh day of life.Results: In all four patients the measured values were lower than the normal levels.Conclusions: Initial observation allow to regard protein C and protein S as important markers of haemorrhagic complications in premature infants, but further investigations are necessary to specify the indications for time-points of laboratory measurements.

Keywords: Protein C, Protein S, intraventricular haemorrhage, preterm newborn