Читать книгу Help Your Baby to Sleep - Penney Hames - Страница 16

• more peaceful sleep

• 50% of all sleep at birth

• 80% of all sleep for adults

• no dreaming

• slow and regular heartbeat and breathing

• harder to wake from

• occurs mostly in the early part of the night for adults

• the immune system is boosted

• physical growth occurs

If you watch your child sleeping, you may notice that there are times when, eyes closed, he seems to be watching some particularly frenetic cartoon. Beneath his eyelids his eyes may flick from side to side and he may frown or smile and wiggle his fingers and toes. If your baby could watch you he’d see the same thing happening from time to time, though not so often. This is REM sleep, which stands for Rapid Eye Movement. This sleep state is also called active sleep. Adults and older children dream during REM sleep but it’s difficult getting a straight answer out of a baby, so there is no way of knowing whether babies do or not.

New-born babies spend about half their sleep time in REM sleep, and babies born before 30 weeks’ gestation initially spend a massive 90% of their sleep time in REM sleep; whereas for you and I, REM sleep only accounts for 20% of our sleep. The point about this is that most of the arousals your baby makes from sleep are from REM sleep. Which explains why premature babies wake more often than term babies and all babies wake more often than adults. However, don’t lose heart if your baby was born prematurely because premature babies are often better than term babies at soothing themselves back to sleep.

As they get older, babies have less REM sleep and therefore wake less often.

When he’s not in REM sleep your baby will, perhaps obviously, be in non-REM sleep or NREM sleep. This sleep state is also called deep sleep or quiet sleep. NREM sleep can be divided into four stages. Stages 1 and 2 are lighter, and stages 3 and 4 deeper and harder to wake from. You are more likely to wake up during stage 2 sleep than in any other part of NREM sleep. In NREM sleep things are more peaceful – no eye movements, with slower, more regular heartbeat and breathing. There is a theory that NREM sleep is the time when bodily processes are restored, when the immune system gets boosted and physical growth can occur.