The Impact of Infectious Diseases on Sleeping Behavior in Preterm Infants
Aims: One of the main reasons for preterm birth is perinatal infection. Preterm infants are very vulnerable and therefore susceptible to contagious diseases. Infection may have an influence on the wake–sleep regulation and the length of the sleep phases. The hypotheses of this study were that the sleep duration is longer and that sleep phases are altered in infected compared with noninfected preterms.
Methods: A total of 40 preterm infants (20 girls, 20 boys, less than 32 weeks' gestational age [mean: 29/1, range: 24/0–37/3] and/or less than 1,500 g birth weight [mean: 1,119 g; range: 420–1,650 g]) were video-recorded for an average duration of 3 hours on several days within the first week after birth and once every following week until they left the incubator. The 277 resulting recordings were scored every 10 seconds differentiating between wakefulness (W), active sleep (AS), and quiet sleep (QS). The total time of each state and the mean duration of a sleep cycle were calculated for every measurement. We performed multilevel linear regression analysis to estimate the association of infection and sleep architecture. To comprehend a recording infected, we considered proven or highly suspected infections of the infant and for all the first-week recording also signs for maternal infection and the main reason for preterm birth. This made 63 infected and 214 noninfected measurements.
Results: There was a positive association between infection and the duration of sleep cycles (p = 0.004), the time asleep (p < 0.001), and the time in quiet sleep (p = 0.025). Furthermore, male participants showed a trend (p = 0.08) toward being less awake and spending more time in active sleep (p = 0.001) than their female counterparts.
Conclusion: In very premature babies, the infectious state significantly affects sleep–wake regulation and the duration of sleep phases. Infected preterm infants generally sleep more, spend more time in quiet sleep, and therefore have longer sleeping cycles.