Cot death and sudden infant death syndrome (SIDS)

Published by Bupa's Health Information Team, April 2011.

This factsheet is for people who have experience of cot death or sudden infant death syndrome (SIDS), or who would like information about it.

Cot death is when a baby under one year old dies suddenly and unexpectedly. If the death remains unexplained after detailed investigation the medical term is SIDS. It's also known as sudden unexplained death in infancy (SUDI).

About cot death

Around 300 babies die suddenly and unexpectedly in the UK every year. Cot death can happen to any baby. But it's more common in babies between one and three months, premature babies, and babies with a low birth weight. It's also more common in baby boys.

Most cot death happens when a baby is asleep in their cot at night. However, it can happen wherever your baby is sleeping, such as when in a pushchair or even in your arms. It can also happen sometimes when your baby isn't sleeping – some babies have died in the middle of a feed.

What happens after a cot death?

If your baby was one of twins, triplets or more, your other baby (or babies) will usually be taken into hospital for observation.

A thorough investigation will be carried out to try to find out why your baby died and to gather information that may help to prevent cot deaths in the future. This investigation is standard procedure in all cot deaths and doesn't in any way imply suspicion or blame surrounding your baby's death.

Many different people are involved in the investigation, including a coroner (an official who enquires into sudden, unexpected deaths), GPs, paediatricians (doctors who specialise in children's health), social workers, police officers, health visitors and midwives.

When the full results from the investigation are available, a case discussion meeting, attended by all of the people involved in the investigation, will take place. This may be up to 12 weeks after the death of your baby.

You will be kept informed of the investigation procedure and progress at all times. At the end of the investigation, a doctor will usually discuss the findings with you.

If a specific cause of death is found, this will be registered on the death certificate. If the cause of death remains unexplained after the investigation, the death is usually registered as SIDS or SUDI. Sometimes the term 'unascertained' will be used.

Causes of cot death

Identified causes

Less than half of all cot deaths have a specific cause. Possible causes include a serious infection, an accident, or a previously unknown problem that your baby was born with (a congenital condition), such as a heart or lung problem.

SIDS

If no specific cause can be found to explain the death of your baby, it's defined as SIDS or SUDI. Research has suggested that a number of different factors may be linked to SIDS. It's believed that these factors don't actually cause SIDS, but may make your baby more at risk. These factors include:

• placing your baby on their chest to sleep
• smoking in the same room as your baby
• allergies
• bacterial and viral infections
• unknown genetic conditions
• problems in the area of the brain that controls breathing
• an irregular heartbeat
• accidental suffocation
• overheating

Reducing the risk of cot death

A campaign to reduce the risk of cot death was launched in 1991 by the Foundation for the Study of Infant Deaths (FSID) and the Department of Health. The recommendations they made have helped to reduce the number of cot deaths reported every year in the UK by almost three-quarters.

Illness

• If your baby is unwell, seek medical advice promptly.
• If your baby has a high temperature, try to keep him or her cool.

Smoking

Exposure to cigarette smoke (during pregnancy or after the birth) is known to increase the risk of cot death. If a baby lives in a household in which one or more people smoke, it more than doubles the risk of cot death.

• Don't smoke during pregnancy – this applies to both mothers and fathers.
• Don't let anyone smoke in the same room as your baby – ask them to smoke outside.
• Don't share a bed with your baby if you or your partner smokes.

Sleeping

For the first six months, the safest place for your baby to sleep is in a cot in your bedroom.

• Always lie your baby on his or her back to sleep.
• Place your baby with his or her feet at the foot of the cot to prevent them wriggling down under the covers.
• Don't fall asleep with your baby while sitting or lying on a sofa or armchair.
• Don't let your baby sleep with a pillow.
• Use a firm mattress with a waterproof cover for your baby's cot.
• Always make sure that bedding is tucked in securely.
• Make sure your baby's head isn’t covered with bedding.

Don't share a bed with your baby if you or your partner:

• have been drinking alcohol
• have taken medication that makes you drowsy
• are very tired

Dummies

There is some evidence to suggest that giving your baby a dummy when you settle him or her to sleep may help to reduce the risk of cot death. However, more research in this area is needed before official recommendations can be made regarding the risks and benefits of using dummies.

If you're breastfeeding, don't introduce a dummy until around one month and try to reduce the use of a dummy gradually when your baby is around six to 12 months to prevent dental problems.

Breastfeeding

Babies who are breastfed are less likely to die from cot death than babies who have only ever received formula milk.

Temperature

Keep your baby at the right temperature.

• The ideal room temperature for your baby is 18°C (a range of 16 to 20°C is acceptable).
• Keep your baby's head uncovered.
• Feel your baby's abdomen (tummy) to check if he or she is the right temperature. If it's hot or your baby is sweating, take off some bedding or clothing. It's normal for babies to have cool hands and feet.
• Always take off your baby's outdoor clothes when you come inside, even if this means waking him or her up to do so.
• Don't let your baby sleep with a hot water bottle or electric blanket, next to a radiator, heater or fire, or in direct sunshine.
• Don't use duvets or quilts if your baby is under 12 months.
• Baby sleeping bags are an alternative to blankets and sheets. Make sure you get the right size and thickness and know what clothes your baby should wear underneath. Always check the manufacturer's recommendations to ensure that your baby doesn't overheat.

Baby breathing monitors

There is no evidence that breathing or movement monitors help prevent cot death and they should only be used on the guidance of a doctor. They can provide a false sense of security and increase anxiety.

Living with cot death

Even after taking as many precautions as possible, babies can and do still die from cot death. You will often have many different emotions, including overwhelming feelings of guilt and anger. Family and friends can be a valuable source of help and comfort at this difficult time. They can also help in practical ways, for example with looking after other children, preparing meals and doing shopping.

Dedicated charities, support groups and associations can provide advice and help to families affected by cot death. It may also help to talk to a counsellor who specialises in helping people cope with grief.

Your GP or health visitor can help you find a suitable counsellor or support group in your area.

Having another child

The decision to have another child after losing a baby to cot death isn't an easy one. You will know if and when you're ready and when it’s the right time for you.

Care of the Next Infant (CONI) schemes are available in many areas. They offer advice, support, increased monitoring for your new baby and frequent check-up visits. Ask your GP or midwife if there is a CONI scheme in your area. If there isn't, your local health authority may run its own equivalent scheme and will be able to offer you additional support during your pregnancy and after the birth of your new child.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.