Preterm brain development and developing executive function - Prof. Nick Embleton

Preterm infants are at increased risk of delayed brain development and have worse cognitive and behavioral outcomes in later life, compared with infants born at full term. In part, this relates to the complexity of brain development, which would have normally occurred in-utero. In the period between 24 weeks gestation and 2 years of age, humans acquire 80–90% of their final adult brain volume. During the second and third trimesters, neuronal migration and programmed cell death (‘apoptosis’) are active processes impacted by nutritional status. In the third trimester, and also throughout infancy, synaptogenesis is key to later brain function, as is myelination, which might not complete until the second decade of life. Damage to the brain by hemorrhage or ischemic damage is common in preterm infants and may impact on the critical brain developmental processes, as could the deleterious effects of disordered development that occur due to the complexities of the neonatal intensive care unit environment and poor nutritional status. Whilst many infants born preterm are recognized to have developmental delay, complications due to impairment of executive function (EF) are less well recognized. EF refers to a set of cognitive processes involved in emotional self-regulation and goal-directed behavior. Deficits in EF may occur even where global development otherwise appears to be normal and may manifest in many different ways.