Incubator covers are increasingly being used in neonatal care as part of minimal disturbance strategies. The aim of this study was to examine possible effects of incubator covers on sleep patterns in stable premature infants. Quiet sleep (QS) can be investigated by amplitude-integrated electroencephalography (aEEG) at 32-34 wk gestational age. In nine premature infants (gestational ages 26-32 wk, median 29) QS periods were measured at a postconceptional age of 32-34 wk (median 34) during two consecutive 24 h periods, one period with a padded dark cover over the incubator and one period without the cover, in a randomized order. There were no significant differences between the two 24 h periods (with incubator cover and without cover, respectively) regarding the duration of the QS periods, the percentage of QS of the total recording time (%QS) or the duration of QS intervals. However, there was a positive correlation between postnatal age in days and the mean duration of QS periods when incubator covers were used (r = 0.90, p = 0.001). When the covers were used there was a difference between the girls and the boys in the duration of QS intervals (p = 0.032); the QS intervals increased in the five girls from median (range) 63.2 (49.4-94.6) min to 77.2 (59.3-100.9) min (p = 0.043). There was no difference in the duration of QS periods between girls and boys.
Conclusion: Incubator covers seem to have some short-term effects on sleep quality in premature infants but the clinical significance and possible long-term effects are not known.