Postnatal adaptation of brain function in full-term neonates as assessed by EEG sleep analyses.

Differences in electroencephalographic (EEG) sleep between preterm and full-term neonatal cohorts at matched postconceptional ages have been previously presented by our study group. These differences may have occurred, however, because of postnatal brain adaptation of the full-term infant after a more recent delivery. EEG sleep analyses, therefore, were performed on only the full-term cohort to determine if EEG sleep measures changed over the first three days after birth, which might account for the differences with the preterm group. Twelve full-term infants studied on the first day of life were compared with 17 full-term infants who were studied on days of life 2 and 3. Using multivariate analysis of variance (MANOVA), comparisons were performed among 13 EEG sleep measures. No EEG sleep differences were seen between full-term children born by Cesarean section versus those born by vaginal presentation. No statistical differences were noted between day 1 compared to days 2 and 3 with respect to 10 measures concerning sleep architecture, phasic, continuity, spectral EEG, and autonomic features. In three EEG sleep measures, changes occurred between days 1 and 2-3, but two of the three measures were in a direction that strengthen our claim that differences exist between preterm and full-term cohorts: more body movements and lower percentages of quiet sleep were noted for full-term infants on days 2-3. EEG sleep differences between preterm and full-term infants at matched postconceptional term ages are more likely to be due to conditions associated with prematurity rather than postnatal brain adaptation in the full-term group who experienced a more recent delivery.