Newborn neurologic maturity relates more strongly to concurrent somatic development than gestational age

The nineteen-item assessment of newborn neurologic maturity developed by Koenigsberger was applied to 682 infants born to women enrolled in a randomized controlled trial of nutritional supplementation in a poor, urban, black, clinic population. The total score of the neurologic scale, four clusters of items derived from principal component factor analysis followed by a varimax rotation, and the four clusters taken simultaneously (using Cohen's method of set correlation) were related to the conceptional age, weight, length, and head circumference of the infants. Taken in any of these ways, neurologic maturity was more strongly related to somatic development than to conceptional age. Although these results are consistent with a set pattern and order of neurologic development, they are incompatible with such a pattern following a rigid and universal time scale. Rather, at all stages of conceptional age, there appears to be a range of neurologic maturity, related more strongly to concurrent somatic development than to the child's conceptional age.