Individual and Gender Differences Matter in Preterm Infant State Development

Abstract

Objective-To further understand state development of preterm infants throughout hospitalization and the effects of selected infant characteristics on state development.Design-Secondary data analysis of a two-group, experimental design study. Setting-Two nurseries in a Northwest medical center.Participants-Ninety-seven (97) hospitalized, medically stable, preterm infants. Fifty one (51) subjects were females.Methods-Two hundred eighty five (285) real-time video recordings of infants performed during 4-hour interfeeding intervals. Sleep-wake states were coded at 15-second intervals.Results-Active sleep was the dominant state across postmenstrual ages. Although not statistically significant, preterm infants showed developmental changes in state organization with increased quiet sleep, drowsy, and awake, decreased active sleep, and more defined and less diffuse states over age. A significant gender effect was found, with males having less active sleep (p = .012), more drowsy (p = .03), more awake (p = 0.43), less defined (p = .002), and more diffuse (p = .001) states compared with females.Conclusion-The predominance of active sleep during the preterm period reflects level of brain maturation. The results emphasize individual variations in state organization influenced by endogenous and environmental factors. Gender differences are potential sources of individual variation.

Unobtrusive sleep state measurements in preterm infants – A review

“…The illumination problem is the same as that discussed in the camera section above. Camera systems have been used to annotate sleep in premature infants (86). However, no automated algorithms were used in most of the cases.…”

Effects of nesting and swaddling on the sleep duration of premature infants hospitalized in neonatal intensive care units

“…[1234567] Adequate sleep is of great importance in neonates as it affects the development of sensory system, the structure of hippocampus, pons, brainstem, middle brain, motor system, limbic, learning, long-term memory, thermoregulation, preservation of the capacity of coping with changes, and appropriate responses to environmental stimulations. [1235] In neonates, the sleep cycle includes three stages of active, quiet, and undetermined sleep.…”

Differences in the Maturation of Amplitude-Integrated EEG Signals in Male and Female Preterm Infants

“…Richardson et al [16] showed that male infants exhibit an increased level of arousability in quiet sleep compared with females. In 2008, Foreman et al [17] reported sex-related differences in preterm infants, showing less active sleep, and drowsier, more awake and more diffuse states in males than in females. Using conventional EEG, Thordstein et al [8] observed less infraslow activity during sleep and more high-frequency activity during wakefulness in healthy female neonates, which might indicate an earlier maturation and lesser vulnerability of the central nervous system of female infants.…”