structure of sleep states

Last reviewed 01/2018

Throughout childhood and adolescence there is a change in the proportion of time in rapid eye movement (REM) sleep and non-REM sleep. These changes are illustrated in the table below :

REM sleep as a proportion of total time asleep

  • premature infant 80%
  • term infant 50%
  • 4 year old 33%
  • at puberty 25%
  • adulthood 20%

Often a newborn baby will start a sleep period by entering into a period of REM sleep. This immature pattern of sleep will alter at about 3 months to one where the infant will begin sleep with a period of non-REM sleep.