Spontaneous awakenings in preterm and term infants assessed throughout 24-h video-recordings.

The study aimed to evaluate the development of awakenings during preterm and term age in 12 low-risk infants observed between 33 and 40 weeks of post-conceptional age. Waking was been detected through the analysis of body motility. Gross generalized body movements with prolonged startles, marked stretching and writhing was considered as waking, whereas vigorous, forceful abrupt body movements with high frequency tremor sometimes superimposed upon movements were considered as corresponding to crying. Total number of awakenings in the 24 h does not show significant changes with age, whereas the mean duration increases significantly, which is accounted for mainly by those awakenings starting with crying, in particular, during the day. These data suggest a developmental gap between the ability to sustain the waking state, which already starts to increase before term age, and the ability to maintain prolonged sleep episodes, which has been shown to develop later. Furthermore, the developmental difference between awakenings starting with crying and awakenings starting with wakefulness suggests that two kinds of awakenings might be modulated by different factors.