INFLUENCE OF GESTATIONAL-AGE, BIRTH-WEIGHT, AND ASPHYXIA ON NEONATAL NEUROBEHAVIORAL PERFORMANCE

The objectives of this study were to determine the influence of birth weight, gestational age, and asphyxia on neurobehavioral performance a t 40 weeks conceptional age, and to demonstrate that this performance may differ in preterm high-risk infants when using low-risk preterm ra ther than healthy term infant norms. A cross-sectional comparative des ign was used to compare neurologic behavior in healthy and high-risk n ewborns at 40 weeks conceptional age using the Einstein Neonatal Neuro behavioral Assessment Scale. Seventy-four high-risk newborns were sele cted from a consecutive sample of asphyxiated, very-low-birth-weight, and small-for-gestational-age neonates. Controls did not fulfill any o f the high-risk criteria and had no pre- or perinatal complications. T here were 37 healthy term and 17 low-risk preterm controls. Statistica lly significant differences occurred between high-risk newborns and te rm controls for the total score (P < .001) as well as for most individ ual items (P < .05). Analysis of high-risk subgroups revealed that sma ll-for-gestational-age and term asphyxiated newborns had the most abno rmal responses. When comparing test performance between preterm high-r isk and term controls, the majority of test items achieved significanc e (P < .05); however, when compared to low-risk preterm controls, fewe r items were abnormal, and the probability level on abnormal items was less significant than expected. This disparity in interpretation of n eurobehavioral status in preterm high-risk neonates using a preterm ve rsus term reference sample warrants further investigation. Appropriate normative standards for preterm infants require definition because it may increase the utility of the neonatal neurologic examination and i ts prognostic value.