Neurobehavioral functioning of healthy preterm infants of varying gestational ages

Little information is available regarding the behavioral repertoire of heal thy, yet prematurely born, infants. To address this problem, the Assessment of Preterm Infants' Behavior (APIB) was used 10 to 14 days after birth in a cross-sectional comparison of 42 healthy newborn infants: 16 full-term in fants (gestational age at birth [GA] = 40 weeks), 13 close to full-term inf ants (GA = 37 weeks), and 13 preterm infants (GA = 34 weeks). Groups differ ed on four background variables that were used as covariates in subsequent analyses. Significant group differences were found on 12 of 29 outcome vari ables, including measures of autonomic, motor, state, attention/interaction , and self-regulatory systems, as well as a measure of overall behavioral o rganization. Pairwise comparison showed that preterm and full-term infants differed on all 12 variables whereas preterm and close to full-term infants differed on 11 of the 12 variables. Furthermore, full-term and close to fu ll-term infants differed on 4 of the 12 variables, including measures of th e autonomic, motor, and state systems. Full-term and close to full-term inf ants were behaviorally more similar to one another than either group was to the preterm infants, yet there were important differences even between ful l-term and close to full-term infants.