Continuity and change in infants’ sleep from 8 to 14 months: A longitudinal actigraphy study

In this report changes and stability in sleep–wake characteristics, at the latter part of infancy, were examined. The sample comprised of 34 healthy infants whose sleep was assessed by means of actigraphy at 8, 10, 12 and 14 months. The results indicated that while sleep schedules did not change significantly from 8 to 14 months, sleep consolidation continued across time. Age 12 months stands out in that sleep disruption was unrelated to whether or not the child was a frequent nightwaker before and/or after the 1st birthday. The findings demonstrate the importance of investigating sleep longitudinally using multiple time scales.

► Sleep was measured longitudinally, in 34 healthy infants, at 8, 10, 12, and 14 months. ► Sleep consolidation increased with age; schedules were consistent overtime. ► 12 months was marked by instability. ► Change and stability in sleep should be studied with multiple time-scales.