The science of sleeping in childhood

Image of Professor Colin Espie
by Professor Colin Espie

Average sleep needs throughout childhood



Every child is different, and every child starts with a different natural pattern of sleep. The guidance for sleep needs on the following pages has been taken from advice agreed by sleep experts in the US for the 'average' child. The experts acknowledged that there is wide natural variation in sleep patterns and needs, especially in the first year of life.

What to expect at different ages..



Newborns 0-3 months



On emerging from the dark and cozy uterus, newborns typically sleep for 30 minutes to 4 hours at a time, for 11 to 19 hours a day. There tend to be no set patterns, and the unpredictability of the next wake time can be particularly challenging. Initially parents need to adapt their schedule entirely to fit their new arrival's needs for food, changing nappies/diapers and nurturing.

At birth, our 'circadian' or 24-hour timing system hasn't developed, so most newborns are no more likely to sleep during the night than the day. After the first few weeks, if your baby still seems to have their nights and days mixed up, you can help to set their internal clock by increasing playtime, social interactions and household noises during the day, but keeping lights dimmed, voices low and stimulation to a minimum in the evening and night.

Newborns don't have the same type of sleep as adults – they tend to be more animated. Newborns spend 50% of their time in 'active' REM sleep which can involve smiles, whimpers and movements, and 50% of their time in quieter, non-REM sleep, but this can still involve startle responses and sucking movements.

At 6-8 weeks, most babies will only manage to stay happy and alert for up to 2 hours at a time. By recognizing early signs of sleepiness, you can start to put your child down to sleep while they are drowsy, but awake. The aim is to help them to become 'self-soothers', able to fall asleep and put themselves back to sleep when they wake at night.

After 8 weeks, sleep during the night should start to consolidate into longer stretches, but for some infants this takes several months.

Signs of sleepiness



• Rubbing her eyes

• Crying or whimpering

• Yawning or stretching a lot

• Pulling or flicking her ear

• Getting faint circles under the eyes

• Staring blankly into space

• Quiet and content after a feed

• Turning away from people and moving objects

Sleep tips for newborns



• Put a sleepy baby down while they're still awake, to help them learn to get to sleep on their own.

• After the first 6 weeks, gradually increase play activity during the day to encourage night sleeping.

• Put babies to sleep on their backs.

• Where possible, sleep when your baby sleeps.

The safest sleeping position to reduce the risk of SIDS (sudden infant death syndrome) is to put a baby to sleep on their back on a firm, flat mattress. Keep soft items like pillows, blankets and quilts out of reach to avoid risk of smothering. Avoid overheating – your baby needs a similar amount of clothing as you are wearing. The risk of SIDS is highest for babies aged between 2 and 4 months.

Infants aged 4 to 11 months



Infants naturally have 'polyphasic' sleep, in multiple stretches over the day. They often take several months to establish a regular sleep and napping routine.

By 9 months, around 60% of children take one nap in the morning and another in the afternoon, and over 70% are sleeping through the night.

Infants typically sleep in 60 minute cycles (and adults in 90 minute cycles), so brief arousals during the night are common. In terms of biological needs, by 6 months, all infants are capable of getting through the night without a night feed. So-called 'good sleepers', who apparently sleep through the night, are actually 'self-soothers' who go back to sleep by themselves after brief awakenings.

'Signalers' signal their wakefulness with a cry, and may need rocking or nursing back to sleep. They will need to gradually learn to get to sleep by themselves (see 'Going Solo').

Sleep tips for infants



• Establish a regular sleep schedule – set a consistent bedtime and wake time. A typical infant bedtime is between 7-8:30pm. Waking the baby for a late feed at 10:30-11:30pm may help reduce early morning awakenings.

• Create a consistent bedtime routine.

• Put a sleepy baby down while they're still awake, to help them learn to get to sleep on their own.

• Avoid consistently feeding your baby just before they fall asleep – start to move feeding to earlier in the bedtime routine.

Toddlers aged 1 to 2 years



Toddlers typically need at least 11 hours sleep every 24 hours. Most toddlers go to bed between 7 and 9pm, and wake between 6:30 and 8am.

Before they are two years old, most toddlers have decreased to 1 nap per day, but don't actively prevent your child from napping – some 3 year-olds still benefit from two naps per day.

As toddlers become mobile and language skills develop, toddlers become more capable of resisting bedtime, and expressing fear or separation anxiety. More than 1 in 4 parents of toddlers are worried about their child's sleep. One in 5 toddlers still wake up regularly during the night.

Many toddlers can feel more secure with a familiar object like a favorite toy or blanket which may help them fall asleep and stay asleep through the night.

Reinforcing good behavior with a consistent approach and a routine schedule become increasingly important.

Sleep tips for toddlers



• Continue to maintain a regular sleep schedule with a consistent bedtime and wake time.

• Create a consistent and enjoyable bedtime routine.

• Put your toddler to bed sleepy, but awake.

• Make the sleeping environment the same throughout the night (see the 'pro-sleep zone').

• Avoid naps after 4pm which can interfere with getting to sleep at night.

Pre-schoolers aged 3 to 5 years



Most preschool children go to sleep between 7 and 9pm at night, and wake between 6:30 and 8am. Many children start to give up naps after their third birthday, but 15% of five year-olds are still napping once a day, and it's important to let children nap if they're sleepy.

As for toddlers, nighttime fears are common, and sleepwalking and sleep terrors peak in preschool years.

Preschoolers can be very persistent when they don't want to go to bed – maintain a consistent approach!

Sleep tips for pre-schoolers



• Maintain a regular sleep schedule.

• Adapt the bedtime routine to include new things your child enjoys, such as playing with specific (quiet) toys or reading books, provided that it still ends in the bedroom. A sticker chart on the wall can help motivate model behavior at bedtime.

• Encourage your child to fall asleep independently.

• A favorite toy or blanket can help encourage a sense of security and encourage self-soothing.

School age: 6 to 12 years



Most school children will have their wake time dictated by the time they need to get ready for school. It's important that bedtime allows for 9-11 hours sleep, though some children will need more.

Sleepiness during the day, mood swings and behavioral problems, could indicate that a child isn't getting enough sleep.

When school starts one of the biggest threats to sleep is homework, both in terms of time and anxiety. Encourage your child to finish their homework early in the evening, so that they have plenty of time to wind down time before sleep.

Many school children are avid media consumers – spending much of their free time on smartphones, the TV or internet. Watching TV around bedtime can be associated with resistance to going to sleep, difficulty falling asleep and anxiety about sleep.

If they aren't sleeping well they may benefit from less time online and more time exercising. One study in 7 year-olds found that for every hour a child was sedentary, they took 3 more minutes to fall asleep!

Sleep tips for 6 to 12 year olds



• Teach children about healthy sleep habits – encourage them to notice how different they feel after a good night's sleep.

• Continue to encourage a regular and consistent sleep schedule.

• Avoid screen time as part of the pre-bed routine.

• Keep the bedroom dark, cool and quiet. Where possible, exclude phones, TVs and computers from the bedroom at night.

Teenagers 13 to 17 years



Recent studies suggest that most teenagers are not getting enough sleep, averaging fewer than 7 hours of sleep. Lack of sleep affects mood, concentration, risk-taking behaviour, diet and immunity from illness. In older teens, lack of sleep has been linked to risk of driving accidents.

Sleep deprivation is likely to arise as a result of a conflict between a teenager's internal body clock, and school or college schedules.

At or around puberty, teenagers naturally become more alert late in the evening – their body clocks shift a few hours back. This means that they may only become sleepy at midnight. With exams, homework, extracurricular activities, social opportunities and after school jobs to keep them occupied, most older teenagers only sleep after 11pm.

The need to rise early to get to school for 8:30am puts sleep time under pressure. Many teenagers build up a sleep debt during the week. While they may attempt to 'catch up' on sleep by lying in at the weekend, they will often be sleepy during the week.

Many teenagers consume caffeinated drinks or pills to stay awake during the day, which can put sleep under increased threat. Alcohol also interferes with sleep.

Sleep tips for teenagers



• Teach teenagers about the science of sleep – let them know lack of sleep can influence their exam results, their relationships and crucially, their safety.

• Don't let a sleepy teenager drive.

• Encourage a regular schedule which allows 8-10 hours sleep, and help your child stick to it 7 days a week, as closely as possible. A consistent sleep schedule will help the body get to sleep faster.

• Teens can still have bedtime rituals. You could checking in before your child goes to sleep to ensure there is nothing bothering them before they go to sleep.

• If possible, keep the bedroom reserved for sleep. If your child works in the bedroom discourage them from working on the bed so that they are better able to switch off from work.

• Encourage your child to be aware of the caffeine content in soft drinks, coffee, tea and any drinks sold as energy enhancers, and to avoid in the hours leading up to bedtime.

• Most teens have autonomy over their bedroom but try to encourage them to maintain a dark, cool and quiet environment at night.

Parasomnias



'Parasomnia' is the term given to unusual behaviors that occur during sleep. For young children, the most common are disorders of partial arousal or wakefulness which happen in the transitions out of deep sleep: confusional arousals, sleepwalking and sleep terrors.

Confusional arousals

These are very common in toddlers and involve noisy and inconsolable thrashing or crying. A child is unlikely to wake fully and will usually return to sleep after half an hour.

Sleepwalking

This is more common in older children. Events can be as simple as getting out of bed to completing complex tasks like making a snack, or even moving furniture. In older children, urinating in cupboards is surprisingly common.

Sleep terrors

As their name suggests, sleep terrors involve the appearance of absolute fear (sweating, eyes dilated, racing heartbeat), often accompanied by a bloodcurdling scream. Some children bolt out of bed. Although they are distressing to witness, children will be unaware that anything has happened when they wake up.

Parasomnias tend to run in families and can be more frequent at times of stress, or if a child is overtired, unwell, or taking medication.

Coping with parasomnias



These events are usually infrequent and mild and stop naturally before puberty but if you are at all concerned that your child's safety is at risk, talk to your doctor for advice.

If your child sleep walks, lock windows and fit gates to stop them falling down the stairs. As far as possible, try to move any furniture or obstacles they might trip over or walk into. The advice is not to wake your child since that will probably prolong the event. Instead, try not to disturb them too much but guide them back to bed if they are mobile.

To reduce the risk of parasomnias, increase the amount of sleep your child gets by increasing naptime or moving bedtime earlier. Stick to a regular sleep schedule.

It's thought that anxiety about sleepwalking or night terrors can actually make them more likely to occur, so the advice is to avoid discussing an event the previous night with your child. If your child is aware, reassure them that their behavior is very common and and not something they need to worry about.

Nightmares



Unlike sleep terrors, nightmares are disturbing dreams which wake your child and leave them with vivid memories. This makes them reluctant to go back to sleep.

Nightmares occur during REM sleep. Most children experience at least one nightmare and 1 in 4 may have repeated scary dreams over a few months.

Coping with nightmares



To reduce the risk of nightmares, avoid reading scary stories or letting your child watch scary movies at night. Ask your child if there is anything worrying them before they go to sleep, and reassure them by leaving a dim light on, or leaving their bedroom door open, if they feel safer.

Ideally comfort your child in their own room, so that they don't get dependent on sleeping in your bed to feel safe. Toddlers are unlikely to be able to understand that dreams are not real. Comfort and reassure them that they are safe. Try leaving on a dim night light and ensure that a toy they are attached to is in reach.

Older children can try strategies such as imagining that they are watching the TV and switching to a new channel, or imagining a dreamcatcher or force field keeping them safe.

Is it something more serious? Recognising sleep disorders



The focus of this guide is on coping with behavioral sleep problems. If you're worried that your child is sleepy during the day despite sufficient sleep, they may have another type of sleep problem. Ask your doctor for advice about sleep disorders.

Narcolepsy



Narcolepsy often first occurs in the mid teens but can occur earlier. It affects about 1 in 2000 children. If is characterized by periods of excessive and extreme sleepiness during the day. A powerful urge to sleep develops, often resulting in a short nap or 'sleep attack'.

These sleep attacks generally last for around 15 minutes, but may last longer, and result in the sufferer feeling refreshed and able to continue their day as normal. Patients with narcolepsy also tend to fall asleep much faster than healthy individuals and may experience the condition alongside other forms of sleep disturbance, for example, sleep paralysis and sleep fragmentation.

Narcolepsy may also present with 'cataplexy', a sudden loss of muscle tone. During these attacks, jaw muscles become slack, the head will suddenly fall forward and the knees will buckle. Attacks are most often triggered by strong emotions such as laughter or anger and usually last for 30 seconds or less, meaning that they may be missed altogether.

Obstructive sleep apnea (OSA)



'Apnea' means the absence of breathing. When a child with OSA is asleep, their upper airway repeatedly narrows or closes, stopping air from getting through. The child may snore or breathe loudly, and may suddenly gasp for air.

OSA is often associated with daytime sleepiness because the sleeper has to wake up briefly to get breathing again, resulting in a very restless sleep. Someone with OSA can wake hundreds of times a night. These partial awakenings might be too brief to see directly, but can be measured in a sleep laboratory.

Children with OSA typically have more trouble breathing on their backs, because the tongue falls back and blocks the air passage, and during the second part of the night during REM sleep.

If you suspect narcolepsy or sleep apnea, ask your doctor for advice.

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