Aim/Methods With the purpose of studying the state of prostacyclin-thromboxane system and its influence on the hemostasis and cerebral hemodynamics the level of thromboxane (TXB2) and prostacyclin (6-keto-PGF1α) was determined in blood by enzyme-linked immunosorbent assay with the help of Enzo Company kits in 20 healthy newborn babies (group 1) and in 134 newborn babies with the cerebral ischaemia of the 2^nd and 3^rd degrees of severity (groups 2 and 3) at birth, at the age of 7–14 days and 1 month.

Results The results revealed several of peculiarities from the aspect of age with the consideration of cerebral deficiency severity. Significant decrease of both parameters in the umbilical blood in the newborn babies of the groups 2 and 3 was determined with the subsequent increase of the content of 6-KetoPGF-1α by the 1^st month of life almost by 8 and 5 times correspondingly that indicated a progressively growing influence of 6-KetoPGF-1α with the considerably lesser age increase of the thromboxane level. Convincing data about the compensatory significance of a low prostacyclin level at birth was received in the healthy newborn babies that defined thromboresistant properties of endotheliocytes.

Conclusions Taking into account the correlation between the size of the vessel lumen and the haemodynamic conditions of the blood flow, it is logical that prostacyclin/thromboxane relation is one of the factors promoting the development of procoagulant properties of the vessel endothelium and, on the contrary, the depression of fibrinolysis. By means of logistic regression analysis the sensitivity and specificity of the prostacyclin/thromboxane coefficient were determined in terms of the possibility of using it to prognosticate severe hypoxic-haemorrhagic lesion in the newborn babies, who had cerebral ischaemia.