Mother and Baby

How to understand your baby’s sleep patterns

How to understand your baby’s sleep patterns

Do you dream of your baby drifting off to sleep by himself? Or your newborn sleeping through the noise of you going to bed? And that he won’t need you again until seven o’clock tomorrow morning?

Sleeping through the night is what we‘re all working towards, supposedly. But this is how an adult sleeps, not a baby. And a baby’s sleep is very different.

All the ‘baby sleep problems’ we talk about are actually normal patterns of baby sleep.

Our babies are simply doing what they’re biologically pre-programmed to do.

Once you know what’s normal for your baby, then you’ll understand what’s happened when he calls for your help in the night, why he needs you right now, and how to help him back to sleep.

And knowing all about his normal sleep patterns will also ensure that, as your youngster grows, you do things that support the development of his sleep, rather than disrupt it. Because one day, he will sleep like an adult.

Your baby has shorter sleep cycles than you

Babies don’t sleep through the night – and neither do adults. We don’t simply go to sleep at night and wake in the morning, getting our sleep in one long chunk. Each and every one of us moves through several cycles of sleep, which as a whole make up ‘a night’s sleep’.

Each of these sleep cycles contains two different phases of sleep. First comes non-Rapid Eye Movement (nREM) sleep. 

This starts as a feeling of drowsiness or a light sleep. And it gets progressively deeper, more restful and harder to awaken from. 

During the next phase, Rapid Eye Movement (REM) sleep, there’s a high level of activity in your brain, and faster brainwaves.

This is the phase of dreams, and if you watch your baby when he’s in this phase of the sleep cycle, you might see his eyes darting around beneath his closed eyelids.

So, you and your baby both start with nREM sleep and move into REM sleep: that’s one complete sleep cycle. And at the end of one cycle, you start a new cycle. 

An adult sleep cycle lasts around one and a half hours. If you get eight hours of sleep (we wish!) you would move through five different sleep cycles. 

But your baby’s cycle is much shorter: at birth, a baby’s sleep cycle lasts for around 45 minutes, and by the age of one it is around 60 minutes.

These shorter cycles mean that babies have roughly twice as many sleep cycles per night as adults, and an average 12-hour night of infant sleep could mean 16 different sleep cycles. 

After every one of these sleep cycles, your baby will return to that drowsy and possibly awake state from the start of a cycle.

There are up to 16 occasions every night when he may wake and need your assistance to get back to sleep.

If he learns that whenever he enters this drowsy state there’s really no need to worry – and that means he finds himself in the same place where he went to sleep, and that you’ll be there if he needs you – he’ll gradually be able to link these cycles together without your help.

Your baby has more REM sleep than you do

As an adult, your sleep cycle is composed of approximately 80 per cent nREM sleep and 20 per cent REM sleep.

But a newborn has 50 per cent nREM sleep, 50 percent REM sleep.

REM sleep is lighter, and more easy to rouse from. So, while your baby is in this phase of the sleep cycle, he might wake more easily in response to noise, light or any other change in his environment.

Even something as simple as the difference in temperature after falling asleep in the warmth of your arms and being placed in the cold of a cot might be enough to rouse him from this light REM sleep.

So, it really helps if you can minimise any stimuli that might rouse him, and keep his environment unchanged, especially in the early days when this proportion of lighter sleep is so high.

All this additional REM sleep also means he’ll experience more dreams. These might disturb him too, and cause him to wake. And then he will seek reassurance from you, to soothe any feelings of fear or anxiety. So it’s important that you give him the comfort he needs if he’s to learn to sleep well.

Your baby was born without a body clock

You have an internal ‘body clock’ which tells you when it’s time to begin and stay in these sleep cycles, and time to end them, and be awake.

This is called your ‘circadian rhythm’, and it’s a continuous circular rhythm that lasts for around 24 hours, and is based on your body’s reaction to the presence or absence of daylight.

When your eyes are exposed to daylight, a signal is sent that triggers the hormone cortisol to be secreted, which helps you feel alert and awake. At night, the absence of light triggers melatonin to be secreted instead, and this lowers your body temperature, which initiates sleep.

When you were pregnant, your baby received a certain amount of your cortisol and melatonin via the umbilical cord, in accordance with day and night-time.

But when he was born, he lost this ‘borrowed’ circadian rhythm. Without it, a newborn can’t tell night from day, and that’s why he’ll sleep erratically over a 24-hour period with no discernible night and day pattern.

He does develop his own circadian rhythm, but it takes time. It’s not until around 12 to 14 weeks of age that it begins to establish itself, and it takes several more months to mature.

To support your baby’s developing body clock, you need to aim to give him as much natural daytime light and night-time exposure to darkness as possible.

So, aim to keep evenings and night-times dark, because it’s not just daylight that initiates the chain reaction that ends in a boost of wide-awake hormones.

Any short-wave blue light triggers it, and this is also emitted from energy-saving light bulbs, televisions, tablets and mobile phones.

Other light sources, such as your baby’s night light or bedtime projector, may also interfere with the secretion of melatonin, and impede sleep.

Do all you can to observe natural levels of lighting during the day too, and this includes not making the daytime artificially dark.

It’s common to use blackout blinds, or sleep shades for car seats or pushchairs, to foster daytime naps. But under-exposure to light in the daytime has been shown to have negative effects on circadian rhythms.

So during the daytime, leave the blinds up and let your baby nap in natural light levels. It may seem counter-intuitive, but exposing your baby to more light in the daytime will have a positive effect on his circadian rhythm and so his night-time sleep.

And be patient too. You can do all you like to ‘teach’ him the difference between night and day, but you’ll also need to wait for the necessary biological processes to happen, and for his body clock to develop.

Having your sleep pattern disrupted night after night is difficult, we know, but understanding why your baby is sleeping like he is will really help you to give him the comfort he needs, and speed you both on your way to contented nights.

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