We often talk about our ‘body clock’, which is technically known as circadian rhythms.
They control our sleep-awake cycle by waking us in the morning during daylight and making us sleepy in the evening when it gets darker.
Light causes us to produce a hormone called cortisol, which keeps us alert and awake (which explains why screen time at night can interfere with sleep).
Darkness switches on melatonin, which makes us drowsy and ready to sleep.
While in the womb, the mother’s circadian rhythm also controls that of her unborn baby.
Once your baby is born, he is temporarily without these hormonal controls, until he begins to develop his own circadian rhythms in the first three months. This means your baby temporarily lives in a world without day or night … and so do his parents!
Newborn Sleep Patterns – What Is Normal, Anyway?
To begin with, we should probably not use the word pattern! The typical newborn has no predictable pattern of sleeping. In fact, the whole sleep/awake cycle appears to be completely disorganised.
Here's what research tells us:
- A ‘sleep’ can last as little as 30 minutes or as long as 4 hours – quite randomly.
- Babies spend a lot of their sleep cycle in active REM sleep, less in deep sleep.
- By four weeks, the ‘average’ baby sleeps for around 14 hours in a 24 hour period, but some sleep as little as 9 and others as many as 19
This really just means you can expect your baby to be awake as little as five hours out of 24 or as many as 15 and still be normal. He will probably have several cat-naps as well as some longer sleep periods, and he will be easily disturbed for most of the time he is actually asleep!
Understanding Your Baby's Fourth Trimester
Dr Harvey Karp is a paediatric professor at UCLA School of Medicine in California, and author of the best-selling book The Happiest Baby. As he noted, when you compare a one-day old baby with a 3 month old baby, you can see the huge changes that occur in just twelve weeks.
By comparison to many other mammals, a newborn human is developmentally immature. Combined with the very large size of the human skull at birth, in relation to the cervix it needs to pass through, he wondered if perhaps our babies must sacrifice some maturity at birth in order to be born before the head is too big to fit.
This ‘fourth trimester theory’ may explain why our babies have this period of time without an efficient circadian rhythm, and why their sleep behaviour is so disorganised and unpredictable. Many families decide to provide ‘womb service’ to their baby during this transition, to allow their baby to adjust to the world gradually.
This means lots of skin-to-skin, baby led feeding, breastfeeding, babywearing, co-sleeping and other gentle parenting techniques can help achieve this. Find out more in BellyBelly's article: The Fourth Trimester – 8 Ways To Create A Great One For Your Baby.
Newborn Sleep Cycles: Why Newborns Are Light Sleepers
Adults and babies have very different sleep processes.
Adults have a sleep cycle of around 90 minutes. During this time, they have a period of REM (rapid eye movement) sleep, followed by deep sleep (before reverting to lighter REM sleep). This is when we either wake up or go back to sleep. It's during REM sleep when we dream, and the brain activity is similar to when we are awake. Early in the night, we have less REM but it increases in the early hours of the morning.
Newborn babies have a different pattern. When a baby first falls asleep, they go straight into REM sleep, which lasts about 20 minutes. During this time, they can easily wake up again. After that period, the baby falls into a deeper ‘quiet’ sleep, when they are less likely to wake. By 50 minutes, they return to REM and either wake or roll into another cycle.
While an adult spends around 20% of their sleep in the light REM sleep, newborns can spend as much as 75% of their daily sleep time in this easily disturbed state.
Why Light Sleep Is Important For Babies
The rapidly growing infant brain needs all this active sleep, and indeed it may even be a protective factor against SIDS! Research by Doctor James McKenna, Professor of Anthropology at University of Notre Dame, studied mothers and their babies as they shared a room or slept in separate rooms. They found that not only did room-sharing pairs share the same sleep cycles, but babies who room-shared experienced more frequent ‘arousals’, triggered by the mother’s movements, and spent less time in deep sleep.
McKenna believes that these low-level arousals — which did not actually awaken either partner — give the baby practice in rousing itself. It may lessen a baby’s risk of SIDS if a baby fails to arouse from deep sleep to re-establish breathing patterns.
This and other research has led to the recommendation that babies share the same room as their mother in the first 6-12 months. Find out more about the work of Doctor James McKenna here.
4 Ways To Help Babies Learn About Night And Day
While you can’t hurry natural development, you can help your baby to be ready for it:
#1: Include Your Baby In Your Daily Activities
Research suggests that babies who are involved in their mother’s routine adapt to the 24 hour day more rapidly. So, keep your baby close by, chat to him as you go about your daily tasks and let him naturally take on your daily rhythm. Babywearing is a great way to do this.
#2: Help Make Night Time All About Sleep
Keep your baby close by having him sleep in your room, so you can quickly respond to his early feeding cues. You will find he won’t always need a nappy/diaper change, and you can minimise waking by changing after a feed (rather than before, when he does need it).
Try using just enough light to see what you are doing. A night-light near your bed will help you to see and feed him. Keep the noise levels low with quiet voices, and minimal conversation with your partner. Of course, there will be times when none of this is possible, but aiming for a calm sleep environment is your goal.
#3: Let The Light In
While your baby is working on that circadian rhythm, you can help by exposing him to natural light during the day. Avoid darkened rooms for naps, getting outside each day, and keeping curtains and blinds open will all help. Not only will you be creating the best environment for your baby to learn the difference between day and night, you will also be supporting your own circadian rhythms and your natural sleep cycle.
#4: Create A Night-Time Ritual
It’s never too early to introduce awareness that day is turning to night. After dinner, dim the lights and reduce household noise when possible. A bath, followed by baby massage, followed with a story or song and a bedtime feed can mark the transition and continue on into childhood.
Living with interrupted sleep is part of parenthood, but there are things you can do to get as much sleep as possible while your baby gets it all worked out. See our tips here.
Recommended Reading: Follow our comprehensive baby week by week series, which will help you understand your baby better. Every week, find out what to expect from your baby when it comes to sleep.