The Development of Circadian Rhythms in Human Infants

Sleep environment of infants
All mothers reported placing their infant supine routinely during night time sleep.
The most common sleep surface was a Moses basket (19 infants which equals 54%).
Just under half of the group were placed in cots (42.9%). Most commonly infants
(80%) infants were in the same room as their parents. One infant co slept (slept in
parental bed). Seven (20%) slept in their own room. Wrappings were light to
moderate with an average total tog (SD) value (clothing and bedding combined) of
7.19. (2.454). The lowest night time temperature in the rooms were the infants slept
(SD) was 19.36 (1.95) o C. The highest average temperature (SD) was 22.24 (1.99) o C.
Sleeping bag use changed as babies got older with infant sleeping bags becoming
more common. Thirteen infants (37%) used a sleeping bag whilst twenty two infants
had no routine use.
3.2 Summary of Data Collected
147 temperature reading were made. 136 were included in the analysis, which made
an average of 4 per infant. The data logger failure resulted in six temperature
readings being discarded. A further 3 sets were not used due to probe dislodgement.
A total of 466 urine samples were collected. 20 were insufficient for cortisol analysis.
4 were not suitable for melatonin estimation. 138 actigraphy recordings were taken.
Of these 135 were analysed. In total 599 samples were processed and analysed for
determination of peripheral gene expression.
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