: The aim of the study was to analyse case report of prenatally unknown asphyxia of the foetus (a preterm newborn from the second pregnancy delivered by urgent caesarean section in 31st gestational week; birth weight 850 grams, birth length 41 cm, value of Apgar score 7/8) with signs of respiratory insufficiency immediately after birth with hypotonicity. The authors present the case of postnatal at the 1st day of life assessed cystic malformation in the brain of premature newborn. They emphasize the importance of detailed prenatal investigation as most important in preventing prenatal asphyxia and consequent complications. Central nervous system and especially white matter of the brain of the newborn is most vulnerable area of the brain. Together with oxidative stress after exceeding of antioxidant capacity belong among main factors that play an important role in the pathogenesis of hypoxic-ischemic encephalopathy.