Cot death: new evidence about bed covers
Publication Date:06/05/2008
Researchers looking for the causes of cot death have found evidence that blankets or bedclothes covering a sleeping baby's head might put the baby at risk. It's important that babies are put to bed in a way that avoids bed covers rising up over their heads.
What do we already know?
Cot death (sometimes called sudden infant death syndrome), when a baby dies unexpectedly without an obvious reason, is thankfully much rarer than it used to be. Far fewer babies die in this way now that parents know to put a baby to sleep on their back, instead of lying on their side or front.
But there are still around 300 cot deaths a year in the UK. So researchers are working hard to find out what else we can do to prevent it.
There have been studies in the past suggesting that bedclothes that cover babies' heads may put babies at risk of cot death. But the results weren't very clear. Now researchers have looked again at all these studies, to see if they can draw conclusions from summarising the results.
What does the new study say?
In the studies researchers looked at, about 25 in 100 babies who died from cot death were found with their heads covered by the bedclothes. By comparison, when parents of healthy babies were asked to check what position their babies were in when they woke after a sleep, only 3 in 100 had their heads covered.
We still don't know for sure that the head covering caused the babies to die. It could be a sign of other things. These types of studies can give us clues about the risks, but they can't tell us for sure.
However, if head covering does play a part in causing these deaths, it could be the cause for as many as one-quarter of babies who die of cot death. So it's definitely worth taking seriously as a possible cause.
We don't know why bedclothes over the head might cause babies to die. In the study, the authors say it's unlikely that it causes breathing problems. But they think it might cause babies to get too hot. Because babies' heads are big compared to the rest of their bodies, they lose a lot of heat through their heads. If a baby's head is covered while they sleep, their temperature might get too high. This might play a part in some cot deaths.
Where does the study come from?
The study was carried out by researchers at the University of Bristol in the UK. It was published in the Archives of Disease in Childhood, a medical journal owned by the British Medical Association.
How reliable are the findings?
The study itself was carried out carefully, but it relies on a lot of studies of varying sizes, some of which were done more than 40 years ago. The results of these older studies varied quite a lot. They all showed that babies who had died of cot death were more likely to have been found with their heads covered than healthy babies. But some studies showed only a small difference, while others showed a very big difference.
It's best to look at this study as one more piece of the jigsaw puzzle. It doesn't give us the full picture, but it gives us a better idea of how we might be able to protect babies from cot death.
What does this mean for me?
Cot death is a terrible tragedy for a family. Researchers are finding out more all the time about how it can be avoided. There's now a lot of advice doctors can give, to reduce the risk of a cot death happening.
Doctors have advised parents for some time now to put their babies to bed in a way that avoids the bed covers rising up over their heads, and makes it harder for babies to wriggle down into bedding. Duvets are not suitable for babies under 1 year old. Light blankets, tucked firmly round the baby, or lightweight baby sleeping bags, are better. Babies should never be put to sleep in an adult sleeping bag.
This study shows that this is sound advice. We can't be absolutely sure that head covering causes cot death, but with something this important it makes sense to take all the precautions you can.
What should I do now?
This is the advice from the Foundation for the Study of Infant Deaths:
- Don't smoke when you’re pregnant, and don’t let anyone smoke in the same room as your baby.
- Place your baby on their back to sleep (not on their front or side).
- Don't let your baby get too hot, and keep your baby's head uncovered while they sleep.
- Place your baby with their feet to the foot of the cot, so they can't wriggle down under the covers.
- Never sleep with your baby on a sofa or armchair.
- The safest place for your baby to sleep is in a crib or cot in a room with you for the first six months.
It's especially dangerous for your baby to sleep in your bed if you (or your partner):
- Are a smoker
- Have been drinking alcohol
- Take medication that makes you drowsy
- Feel very tired;
or if your baby:
- Was born before 37 weeks
- Weighed less than 2.5 kilograms (5.5 pounds) at birth
- Is less than three months old.
Blair P, Mitchell E, Heckstall-Smith E, et al. Head covering: a major modifiable risk factor for sudden infant death syndrome: a systematic review. Archives of Disease in Childhood. Published online 1 May 2008.
To find out more, read our information on cot death.
News Archive
© BMJ Publishing Group Limited ("BMJ Group") 2007. All rights reserved
This information does not replace medical advice. If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.
