Sleep stage transition and changes in autonomic function in newborn infants.

The relationships between sleep stage, startle response, electroencephalogram (EEG) pattern, and autonomic function in sleeping full-term infants was examined. Using autoregressive analysis of heart rate variability (HRV), 12 infants at a mean post-conception age of 41.1 weeks were studied. Based on HRV characteristics, the present study shows sympathetic nervous system activation during active sleep (AS) and distinct changes in autonomic function based on the startle response and EEG features during quiet sleep (QS). The findings might reflect structural and functional maturation of the central nervous system of newborn infants.