Understanding your baby's sleep

How much sleep do babies need?

Babies need a lot more sleep than adults when they are very young. On average, babies under three months sleep twice as much as their parents, but half of this will be in the daytime.

Young babies do not get all this sleep in one long stretch, though, because they need to wake up for feeds. For the first three months of their lives, babies sleep in sleep-wake cycles through the day, with longer stretches at night.

The length of these cycles varies greatly from baby to baby, but on average your baby will sleep for blocks of about two hours in the day, and four to six hours at night. Find out more about how much sleep your baby needs.

What are the phases of sleep?

Like us adults, babies go through phases of sleep. Even though many of us feel we sleep like a log, in fact, we do not simply fall into a deep sleep all night and then wake in the morning.

Instead, we "cycle" through levels of sleep, from drowsiness down through light sleep and dream sleep into deep sleep. Then we come back up again through dream sleep and light sleep to the surface before going down again.

Dream sleep is also known as rapid eye movement, or REM, sleep. Babies and adults move through this sleep cycle about five times a night.

These phases of sleep appear in babies even before they born. Your baby will have had dream sleep while she was still in your uterus, when you were about six or seven months pregnant with her.

You can easily see the difference between dream sleep and non-dream sleep in her now. In dream sleep, you can see her eyes darting back and forth under her eyelids, the rest of her body is still except for occasional twitches, and her breathing is irregular.

In non-dream, or quiet sleep your baby will breath deeply and regularly, sometimes with a big sigh. She will lie very still, but may make little sucking movements with her mouth or suddenly give a start. These sudden movements of the whole body are known as hypnagogic startles and are perfectly normal.

They happen in older children and adults, too, often when you are just dropping off to sleep. Although this quiet, non-dream sleep is well formed in newborns, it occurs in short bursts instead of a continuous flow. During the first month of life the non-dream sleep phase will gradually become more continuous and the startles will disappear.

Does my baby dream a lot?

Young babies have considerably more dream sleep than adults. According to US sleep expert Dr Richard Ferber, premature babies spend about 80 per cent of their time in REM sleep and 50 per cent by the time they are full term. This drops to 33 per cent by the age of three and to adult levels of 25 per cent by 10 to 14 years.

Dream sleep is thought to be an important time for filing away all our experiences, so it is particularly vital for a rapidly growing and developing baby.

How will my baby's sleep change?

Between three months and a year your baby will gradually sleep more during the night and less in the day. At three months she will, on average, be sleeping twice as long at night as in the day.

Daytime naps will gradually become a little longer and less frequent by six months. By then, most babies enjoy about 12 hours at night with the odd brief waking, and two one to two-hour daytime naps.

By 12 months many babies still sleep 12 to 14 hours altogether, including one daytime nap. Over the following year this nap may be dropped.

How can I manage my baby's naps?

Managing your baby's naps can be key to good sleeping habits. If your baby has a nap late in the day it can interfere with the following night's sleep. This is probably because much of your baby's dream "filing" of the day's stimulation is completed during nap time. This means that her "filing basket" for dreaming is a little empty for the night's sleep.

It is therefore wise to keep her main naps in the early part of the morning and afternoon and, as she gets older, to have her main nap shortly after lunch with a substantial gap before bedtime. This way she'll have time to build up a new stock of experiences to file away.

What are my baby's natural sleep rhythms?

Most babies are physically capable of sleeping through the night from six months although this varies considerably. Even newborn babies are familiar with a long, still and quiet night.

They have been listening to the sounds of the family through the wall of your uterus (womb) for about two months before they are born. Don't worry about tiptoeing quietly around the house during the day, as your new baby is comforted by all those familiar family sounds.

Like you, your baby's sleep-wake cycle relates to her daily rhythm of feeding, body temperature and hormone release. All these things influence the natural biological cycle, or circadian rhythm, our bodies pass through every 24 hours. We fall asleep as our level of adrenal hormones and temperature drop, then we come to wakefulness as our levels of hormone and body temperature rise.

It's actually quite difficult to fall asleep when our body temperature and hormone levels are high and equally difficult to wake up if they are low. This is why we get jet lag when we travel across time zones, and why shift workers have to train themselves to manage their unusual hours.

Some individuals are better at this than others, which explains why some parents find it harder than others to cope with their baby waking at night.

What about feeding and sleep?

Like us, babies over three months need to begin to learn to shut down their digestive system at night and wake up for their breakfast at the same time each day. It can be confusing to their system if they expect to have a bottle of milk to get them off to sleep in the night-time. It is the sucking which settles them, but then all that milk then needs digesting.

A more practical approach is to begin separating feeding from sleep at about three months. If you are breastfeeding, try to give your baby her last feed earlier in the evening, or at the start of her bedtime routine.

If you are bottle-feeding you can gradually decrease the amount of formula you give your baby at her last feed, and add that volume to other feeds during the day. At the same time, your baby can begin to learn new bedtime habits, such as having a bath, putting on pajamas and listening to a story or a song before being left to doze off.

How can I get my baby to go to sleep on her own?

It isn't helpful to stay around as your baby drops off to sleep, as she will start to associate you with going to sleep. This means she'll want you each time she comes to the surface in the night - normally five times, remember!

So give a kiss goodnight and leave the room. If necessary just look in and offer some reassuring words or pats on the belly until she has finally fallen asleep. Read about other strategies which might help your baby to sleep through the night.

Written by Dr Olwen Wilson
Dr Olwen Wilson is a consultant child psychologist at the Royal Surrey County Hospital in the UK and has a specific interest in childhood sleep problems.