What is the risk of cot death?

Cot death occurs most often, though not always, during sleep. This may be overnight in the cot, but it could be during a nap at any time of day, in a pram or even in a parent's arms (FSID 2009b) . Also, cot death is more common in the winter (FSID 2008) , though the reasons for this are not yet fully understood.

Which babies are most at risk?

Cot death is uncommon in babies less than a month old. It is most common during the second month and nearly 90 per cent of cot deaths occur in babies under six months old. The risk reduces as the baby grows older - very few cot deaths occur after a year (FSID 2009b) .

Cot death can affect any family, although it is very rare for it to occur twice in the same family, and it is uncommon in Asian families, for reasons that are not yet understood (FSID 2009b) .

The rate of cot death is highest for babies of mothers aged under 20 at the time of the child's birth (FSID 2008) . There are other factors that you can't change that put a baby at a higher risk of cot death. These include:

• being a boy – cot death is slightly more common in boys: almost 60 per cent of cot deaths are in boys (NHS 2007)

• being born prematurely (before 37 weeks) (NHS 2007)

• being born at a low birth weight (less than 2.5kg/5lb 8oz) (NHS 2007)

How can I reduce my baby's risk of cot death?

Sadly there's no way to prevent cot death. However, you can do a number of things to decrease your baby's risk. The Department of Health (2009) recommends the following steps:

Put your baby to sleep on her back, in a cot in a room with you
This is the safest place for your baby to sleep. Healthy babies placed on their back to sleep will not choke. Putting your baby on her side is not as safe as placing your baby on her back.

At around five or six months, babies start to roll , and at this age the risk of cot death reduces and it's safe to let your baby find her own comfortable sleeping position . But you should still put your baby down to sleep on her back. If you wake up and see that your baby is on her front, gently roll her on to her back; but you don't need to get up and check throughout the night.

Don't smoke during pregnancy or allow anyone to smoke around your baby
If you smoke cigarettes during or after pregnancy, your baby's risk of cot death will be increased. Cot death is more common in babies of mothers who smoked or who were exposed to smoke when pregnant, and in babies who are exposed to smoke themselves. One study predicted that up to 40 per cent of cot deaths could be prevented if pregnant mothers did not smoke (Kirsten et al 2000) .

Don't smoke during pregnancy and don't allow smoking around your baby. The risk to your baby is increased if anyone in the house smokes, even if it's in another room, with a window open or with a fan or ioniser. Ask visitors to smoke outside, and always keep the air around your baby smoke-free.

Don't let your baby get too hot
Overheating your baby is linked to an increased risk of cot death. Keep the room your baby sleeps in at a comfortable temperature (between 16 and 20 degrees C/61 and 68 degrees F, ideally 18 degrees C/64 degrees F). Babies should not sleep next to a radiator, heater or fire or in direct sunlight. Don't use a hot water bottle or an electric blanket.

Lay your baby with her feet at the foot of her cot ("feet to foot") so she can't wriggle down under the bedding. Keep her head uncovered by tucking her bedding in no higher than her shoulders. If you use a sleeping bag, make sure it is well-fitting so your baby can't slide down inside.

Signs that your baby may be overheated include sweating, damp hair, heat rash , rapid breathing, restlessness, and fever . Feel your baby's tummy or neck to see if she is getting too hot or too cold and adjust her bedding accordingly. Don't feel her hands or feet to work out if she is warm enough; it is normal for them to feel cold anyway.

Remove your baby's hat and any extra layers of clothing as soon as you come indoors after being outside, even if it means waking her.

Never sleep on a sofa or armchair with your baby
After a cuddle or a feed, put her back in her cot. In her first six months the safest place for your baby to sleep is in a cot or crib in a room with you.

Sleep your baby on a firm, flat mattress that is clean and fits the cot well, without gaps at the edges. Waterbeds, beanbags, baby nests, fleeces and other soft surfaces are not suitable for your baby to sleep on. The outside of the mattress should be waterproof and covered with a single sheet.

For bedding, use a sheet and cellular blankets rather than a duvet, or a well-fitted lightweight baby sleeping bag. Sleeping bags should not be big enough for your baby to slip down inside.

If your baby's too hot, remove a blanket; if he's cold, add one (remember, one blanket folded in half is two layers). Do not use duvets, quilts, bedding rolls or pillows.

Breastfeed your baby
There is new evidence that breastfeeding reduces the risk of cot death in babies (McVea et al 2000, Ip et al 2007) . Breastmilk gives babies all the nutrients they need for their first six months of life and helps protect them from infection (Department of Health 2009) .