In a prospective study 325 risk newborn infants were examined by means of ultrasound scanning. Children with and without intracerebral haemorrhages were classified, according to pre-, intra-, and postnatal periods of oxygen privation. For the characterization of short-term hypoxia the blood-gas analysis was used for the ascertainment of longtime hypoxia the erythrocytic-density-test (EDT). In dependence on PO2-values less than or equal to 5 kPa intracerebral haemorrhages of variable states increased significantly (p = 0.01). Evaluating the results of erythrocytic-density-test it may be concluded that the prenatal hypoxia has the greatest influence on the rate of intracerebral bleedings. Thus only 37.5% of our patients with prenatal hypoxia remained free of haemorrhages, in contrast of 70.2% of children without deficiency of oxygen.