Cognitive and behavioral deficits in premature graduates of intensive care

The survival rates of very low birth weight (VLBW) infants, including those born at the cutting limits of viability, continue to improve [1-3]. It has become increasing apparent as follow-up has extended into school age and young adulthood, that a large number of such infants are exhibiting neurobehavioral problems [4-15]. Thus it is estimated that the academic achievement of approximately 30% to 50% of ex VLBW children is in the subnormal range, fewer graduate from high school, 20% to 30% exhibit the attention deficit hyperactivity disorder, and approximately 25% to 30% are affected by psychiatric disorders at adolescence [4-15]. This has occurred when there has been a concomitant reduction in the occurrence of known neonatal neurosonographic correlates of adverse outcome (ie, severe intraventricular hemorrhage) [16-18]. Potential contributing factors include the inherent vulnerability of the premature brain during a critical period of development, numerous medical problems and treatment strategies specific to prematurity, and stressful environmental conditions. This article focuses on the pathogenesis and potential clinical and stressful environmental factors that are predisposing to long-term neurobehavioral problems in VLBW infants, in the absence of overt neurosonographic abnormalities.