What is cot death?
Cot death is a term commonly used to describe a sudden and unexpected infant death that is initially unexplained.  The equivalent medical term is 'sudden unexpected death in infancy' (SUDI). Some sudden and unexpected infant deaths can be explained by a thorough postmortem examination and other investigations. Cot deaths that remain unexplained after a thorough examination are usually registered as sudden infant death syndrome (SIDS). Sometimes other terms like sudden infant death, sudden unexpected death in infancy (SUDI) or unascertained may be used.

What causes cot death?
A thorough post mortem examination will reveal a specific cause of death in less than half of all cot deaths. Causes may include accidents, infection, congenital abnormality or metabolic disorder. For the cases that remain unexplained (SIDS), researchers think there are likely to be undiscovered causes.  For many it is likely that a combination of factors affect a baby at a vulnerable stage of development.

Do babies only die at night in their cots? 
No, cot death can occur anywhere and at any time. Cot deaths do however usually occur during a period of sleep in their cot but babies can die during any other period of sleep in their parent’s arms or in a pram.

Do babies suffocate?
When babies are found dead in their parents’ bed or with their faces covered it is sometimes thought they have died from suffocation.  It is not known how often suffocation is in fact a total explanation for the baby’s death.

Do babies suffer any pain?
No, most die peacefully in their sleep without pain or distress.

Does it only happen to certain babies?
No, cot death can affect any baby, but certain babies are more at risk, namely premature and low birth-weight babies and boys, and later babies born to mothers who are still young.

What is the usual age for cot death?
Cot death is uncommon in babies less than a month old, but rises to a peak during the second month. The risk then diminishes as the baby grows older. Nearly 90% of cot deaths have occurred by six months, and very few occur after a year.

Does cot death run in families?
Cot death can happen to any family, though it is more frequent in families who live in difficult circumstances or who smoke a lot.  It is uncommon in Asian families, for reasons that are not yet understood.  It is very rare for cot death to occur twice in the same family, though occasionally an inherited disorder, such as a metabolic defect, may cause more than one infant to die unexpectedly.

Why are the police involved?
The law requires that a coroner investigates all sudden and unexpected deaths in infants (and adults) to certify the cause of death. The coroner's representative, usually a police officer, will ask the parents for information. The police are authorised to investigate unexpected deaths; they usually visit the home, and may sometimes take photographs and remove items such as bedding. 

Is there any support for parents who have had a cot death and are having another baby?
Yes, the Care of the Next Infant (CONI) programme, run by FSID in conjunction with the NHS in 91% of the country.  This scheme offers advice, support and practical help to cot death parents in the care of their next baby. This programme is also available to families whose babies have died for other reasons, the extended families of cot death babies, and parents of babies who have experienced Apparent Life Threatening Events (ALTEs).  Ring FSID's Helpline on 020 7233 2090 or email for more information about the CONI programme.

What research is being done?
Most of the research into cot death in and has been funded by FSID. Since it was founded in 1971, FSID has spent around £10 million on research. All research funded by FSID is rigorously assessed by independent scientists and doctors. We believe that, in order to reduce the rate of cot death further, we also need to understand what makes babies healthy. Research currently being funded is looking at:

• Prematurity, maternal smoking, infant sleeping position and SIDS
• Whether genes have a part to play in sudden infant death
• The impact of depression and maternal personality disorder on early infant care
• Death scene investigations after sudden unexpected infant death
• Factors associated with the early onset of spontaneous labour and SIDS
• Antenatal and postnatal physiological development and its effect on infant care

Is cot death on the decline?
The rate remained fairly constant in and at about two per 1,000 live births from 1971 to 1988, and then began to decline. The rate has fallen by around 65% since the advice on reducing the risk of cot death started being known from 1988. However 300 babies died suddenly and unexpectedly in the UK in 2005 making cot death the largest kind of death in babies over one month old.

How does cot death compare with other childhood problems?
Cot death remains the most common kind of death in babies aged over one month old.  Far more babies die as cot deaths each year than from road traffic accidents, leukaemia and meningitis put together.

How does the cot death rate compare with other countries?
It is similar to countries such as France, Norway and Sweden. The rate is lower in the Netherlands and Japan, but higher in New Zealand, Australia and the USA.  In recent years the rate in many industrialised countries has declined, as in the UK, following the introduction of Reduce the Risk campaigns.

At what time of year do cot deaths occur?
Cot deaths can occur at any time of year.

How can you reduce the risk of cot death?
There are a number of key steps you can take:

• Cut smoking in pregnancy – fathers too! And don’t let anyone smoke in the same room as your baby.
• Place your baby on the back to sleep (and not on the front or side).
• Do not let your baby get too hot, and keep your baby’s head uncovered.
• Place your baby with their feet to the foot of the cot, to prevent them wriggling 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, even if you never smoke in bed or at home
- have been drinking alcohol
- take medication or drugs that make you drowsy
- feel very tired;
or if your baby:
- was born before 37 weeks
- weighed less than 2.5kg or 5½ lbs at birth.
• Don’t forget, accidents can happen: you might roll over in your sleep and suffocate your baby; or your baby could get caught between the wall and the bed, or could roll out of an adult bed and be injured.
• Settling your baby to sleep (day and night) with a dummy can reduce the risk of cot death, even if the dummy falls out while your baby is asleep.
• Breastfeed your baby. Establish breastfeeding before starting to use a dummy.