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Is bedsharing dangerous? Talking about risks

bedsharing cosleeping safe baby sleep
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Is bedsharing dangerous? Talking about risks

bedsharing cosleeping safe baby sleep
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Parents want to make the best choices for them and their family, and so safety is something that they think about a lot. Sleep safety is something parents hear a lot about, but, until recently the only bedsharing advice parents were given was ‘don’t do it, it’s dangerous’. This meant it was really hard to find good information about bedsharing, and how to do it safely. Without information on the risks of bedsharing, and how to make it safe, parents weren’t able to make informed decisions.

This meant some parents turned to more risky sleep options in an attempt to avoid bedsharing. Others embraced bedsharing as a necessity, but without access to reliable information about risks and how to manage them.

Is bedsharing dangerous? Understanding risks.

Firstly, bedsharing is not a single uniform practice. Everyone’s set up is a bit different. Some people have a bed with gaps that a baby could fall down, and a thick duvet, whilst others may use blankets and sleep on a mattress on the floor. These scenarios have different levels of risk.

Everything has a risk

The other thing to remember is that everything has a ‘risk’ associated with it, we just often don’t think about them. What are the risks associated with a baby sleeping in a cot? What about leaving a baby under 6 months to nap in the lounge whilst you pop through to the kitchen? Is that more or less risky than you taking a nap with them on a firm mattress with no blankets or duvets?

What about allowing a baby who has fallen asleep in a bouncy chair to nap there? What about using a bed nest pillow for a baby to sleep in at night unobserved? Is that more or less risky than bedsharing?

Every choice has a level of risk associated with it. When we know what the possible dangers are, and how likely they are, we can make better informed choices about risks.

The statistics

In 2014 and 2015 50% of SIDS deaths were in a cot or crib, and 50% were in a parental bed. Of the 50% in a parental bed, 90% of these were in hazardous bedsharing situations.

Now, we do not know how many babies are usually in their parents’ bed so we can’t directly compare these figures. What we can see is that relatively few babies die in a parental bed in a safe bedsharing setup. So, by reducing hazardous cosleeping we can reduce the risk of death whilst bedsharing.

The most recent UK study (the Southwest Infant Sleep Study (SWISS)) (conducted between 2003 and 2006) found that smoking, alcohol use and sofa-sharing explained the risk associated with SIDS deaths that happened when babies were co-sleeping with an adult.

Hazardous cosleeping environments and risk factors amenable to change: case-control study of SIDS in south west England. Blair et al, 2009. Quoted in

Most statistics about bedsharing include sofa sleeping. Sofa sleeping is the highest risk baby sleep set up. Including this very high risk practice under the heading of bed sharing, even though it does not occur in a bed, has made it harder to get accurate data about bedsharing risks. The SWISS study cited above suggests that bedsharing does not necessarily come with an increased SIDS risk than sleeping in a cot, unless the adult has been using alcohol, smokes, or smoked during pregnancy, or if they are using an unsafe sofa sleeping set up.

Sofa sharing: the highest risk sleep set up

There are a few things that makes sleeping on sofas or in armchairs with a baby very high risk.

Sofas are soft and squashy, rather than firm. They create small gaps that a baby can slide or roll into and become stuck between you and the sofa/chair causing crushing or suffocation.

A recent UK study (conducted between 2003 and 2006) found that 16% of SIDS babies had died while sleeping with an adult on a sofa. In comparison, only 1% of the control babies (a matched-comparison group of babies who did not die) slept on a sofa with an adult.

The average chance of SIDS in England and Wales is 1 in 3,300, but the chance of SIDS while co-sleeping on a sofa is 1 in 180. We therefore strongly encourage you to avoid co-sleeping with your baby in hazardous locations such as on a sofa.

Sofa-sharing severely increases the chance of SIDS, and we would strongly suggest that you find a safer option for your and your baby’s sleep, whether that is bedsharing, or not.

Why bedsharing happens?

Bedsharing is common. Most parents do not plan on bedsharing before their baby is born, however, for many reasons they do.

50% of families sleep with their baby at least once in the first 3 months,* and this rate is 75% for breastfeeding families.**

*Reasons to bed-share: why parents sleep with their infants. Ball, 2002.
**Recent studies include Bed-Sharing at 3 Months and Breast-Feeding at 1 Year in Southern Brazil. Santos et al, 2009;

On any given night a fifth of all UK babies spend at least part of the night sleeping with one or both of their parents. 

The prevalence and characteristics associated with parent-infant bed-sharing in England. Blair & Ball, 2004

Often bedsharing happens because parents struggle to put their baby down in their own sleep space without them waking up. Babies are well known for waking frequently at night. Until parents are in that situation though, they often don’t realise how overwhelming that lack of sleep can be.

Babies expect to be close to their parents day and night. It is the biological norm. It is the way we have evolved throughout human history. Being close to parents, often actually in physical contact, is how most babies are calmest. For many families bedsharing becomes a sleep tool.

In some families the baby will sleep with a parent every night. For other families bedsharing is used occasionally. Often this is when babies are ill, teething, or feeding a lot during a growth spurt. During these times of increased disturbance bedsharing may be a temporary way to get more sleep, with the baby coming into the bed part way through the night when they become upset and hard to settle.

What are the risks of bedsharing?

When we are talking about sleep safety and dangers we are usually talking about death. As soon as we start talking about infant death fear levels ramp up. Of course they do, it is every parent’s worst nightmare. However, we need to talk about these risks as clearly as possible.

Sudden Infant Death Syndrome (SIDS)

Every parent should be given sleep safety advice that specifically talks about SIDS. SIDS is Sudden Infant Death Syndrome. It is unexplained, so it is not caused by smothering or suffocation, like if a baby suffocates under a cuddly toy in their cot, or if they are crushed in a sofa sleeping accident. Those deaths have other explainable causes. SIDS is when a baby dies whilst asleep and there is no apparent reason for this to have occurred.

SIDS can happen when a baby is sleeping in any situation: a cot, push chair, or a parent’s bed. There are some risk factors that seem to increase a baby’s chance of SIDS in one sleep scenario or another.

Smothering or suffocation

The risks that are often particularly associated with bedsharing are smothering or suffocation. This is because in a cot of basket parents tend to use safe breathable blankets, without pillows or other objects that could could a baby’s mouth or nose.

In a parent’s bed bedding is usually thicker and heavier, and there are usually pillows. If any of these cover the baby’s airways they are at risk of being suffocated.

Another risk factor is the parent. A sleeping parent who rolled onto their baby, or rolled over in their sleep, pulling the duvet up over their baby’s face creates suffocation and smothering risks.

Bedsharing risk factors

The following factors increase risks whilst bedsharing.

  • Bedsharing with an adult who smokes. (Probably because smokers tend to sleep more deeply and are less aware of the baby in the bed.)
  • Bedsharing with an adult who has drunk alcohol. (Increases the risk of SIDS and accidental death. Alcohol makes people less aware of their surroundings and encourages deeper sleep.)
  • Bedsharing with an adult who has taken medication that increases drowsiness.
  • Bedsharing with an adult who is excessively exhausted increases risks because it changes their normal sleep patterns.
  • Baby’s whose parents smoked whilst pregnant, have a higher risk of SIDS in general, and whilst bedsharing.
  • Formula feeding can be a risk factor. This is because chestfeeding or breastfeeding parents are more likely to adopt the protective bedsharing sleep position. This is an adult sleeping on their side with their legs drawn up below a babies feet and their arm out preventing any pillows, if used, from migrating downwards towards their baby, with their baby at nipple height. Breastfeeding parents who do not adopt this position may increase risk, and formula feeding parents who do adopt this position may not. It is not as simple as formula feeding increases risks.
  • Premature or low birth weight babies may be at higher risk of SIDS when bedsharing, even with non smoking parents. They are at significantly increased risk when bedsharing with parents who do smoke.
safe bedsharing position
The protective bedsharing position: image from the BASIS cosleeping image bank.

Triple risk hypothesis

Much of this information is from BASIS, the Durham University research centre. They have come up with the triple risk hypothesis, which recognises that SIDS generally occurs when three risk factors occur simultaneously. These are age: most SIDS deaths occur between 2 and 4 months; vulnerability: this could be prematurity or low birth weight, or exposure to smoking in the womb, or an heart condition or similar; and environmental factor, for example, overheating, soft bedding or exposure to smoking after birth. Read more about the triple risk hypothesis from BASIS.

Managing risks and making informed choices

As parents we can consider what our baby’s risk profile is: are they in the 2-4 month old peak risk age range? Do they have any known vulnerabilities? What environmental risks are present, and can we reduce these?

Is bedsharing a good option for us, now, given these factors?

How can we reduce the modifiable risk factors to make bedsharing as safe as possible?

When do we consider the risks too high? For example, if our baby is aged between 2 and 4 months was premature, has a known breathing issue, the weather is very hot, and we have drunk alcohol, we may consider that to be too many risk factors, and avoid bedsharing.

Everyone will have different cut off points and different risk profiles. Consider your risks and ensure you are comfortable with your sleep set up to maximise sleep and safety.

Set up safety

Read our Bedsharing safely article, to help you to create the safest bedsharing set up for your family.

Want to support parents with sleep?

If you are passionate about supporting parents with the reality of parenting, love sharing evidence backed information about the reality of sleep, and want to support parents to find ways to meet their own and their baby/child’s sleep needs then training with CalmFamily as a sleep specialist may be right up your street!
Find out more about training to offer SleepCalm today.

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