Premature birth and the early exposure to environmental sensory information influence the cascade of histogenetic events that occur during the development of human telencephalon. The prenatal establishment of the genetically driven number and size of the elements that constitute the neuronal architecture of the telencephalon (e.g. number of axonal fibres and neurons) is the basis for the lifelong neuronal reorganisation (e.g. synapse pruning, dendrite growth, axonal retraction and myelinisation). Our hypothesis was driven by the experimental data and data from literature according to which the results of early alteration of histogenetic prenatal events can be seen in childhood too. Thus, we have tested the effect of the premature birth and birth weight on the regional size of cerebral cortex (cortical thickness and cortical surface) at school age.