Neurological and neurobehavioural differences between preterm infants at term and full-term newborn infants.

A detailed neurological and neurobehavioural examination was done in 80 preterm infants of 27 to 35 weeks gestation in the first week of life and again at 40 weeks postmenstrual age, and in 40 appropriately-sized full-term infants on the first and fifth days of life. There were several consistent differences between the preterm infants reaching term and the newborn full-term infants. The preterm infants reaching 40 weeks showed less flexion in their posture, and less arm traction, arm recoil and leg recoil than the full-term infants on day 1, although this difference was less apparent by day 5. The preterm infants appeared not to develop the flexor tone of the full-term newborn. The preterm infants demonstrated better visual and auditory orientation and alertness than the full-term infants. The significance of these findings, both for initial neonatal examinations and for subsequent assessments, is evaluated.