Sudden infant death syndrome (SIDS)
Sudden infant death (SID), sometimes known as cot death, is the sudden, unexpected and unexplained death of an apparently healthy baby.
About Sudden infant death syndrome (SIDS)
Sudden Infant Death Syndrome is rare and the risk of your baby dying from it is low.
However, some babies are at higher risk of dying unexpectedly in infancy.
These include babies:
- from multiple births, born prematurely or small for gestational age
- whose parents smoked during pregnancy and/ or after the birth
- born into households living with vulnerabilities, including deprivation and substance misuse
- sleeping in an unsafe sleep environment
Most deaths happen during the first six months of a baby’s life.
SIDS also tends to be slightly more common in baby boys.
SIDS usually occurs when a baby is asleep, although it can occasionally happen while they're awake.
Most, but not all, sudden infant deaths are preventable.
Most sudden Infant deaths are preventable.
Parents can reduce the risk of SIDS by:
- creating a clear, flat safe sleep space and always placing the baby on their back for all sleeps
- keeping babies smoke free - not smoking while pregnant or after the baby is born
- breastfeeding if possible, as this is protective
- never sharing a bed with an infant if you have been drinking alcohol or taken any drugs or medication that would lead to heavier sleep
- not sharing a bed with your baby if they were born prematurely and you smoke
Find out how to stop smoking at the link below:
Causes of SIDS
The exact cause of SIDS is unknown. It's thought to be down to a combination of factors.
Sudden infant death syndrome occurs when a sleeping, seemingly healthy infant less than one year of age, dies for no apparent reason.
Three key factors increase the risk of sudden infant death:
- physical vulnerability of the baby
- social complexities
- sleeping environment
Physical vulnerability of the baby
Babies are more at risk of sudden infant death if they have a physical vulnerability.
This includes babies:
- from multiple births, born prematurely or small for gestational age (less than 37 weeks and below the 10th percentile)
- whose parents smoked during pregnancy and/ or after the birth
- never breastfed, less than 6 months old, and male
Social Complexities
Babies with social complexities are also more at risk of sudden infant death.
This includes babies born into households living with vulnerabilities, such as deprivation, poor housing, substance misuse, and other social vulnerabilities including being a young and/ or unsupported parent.
Sleeping environment
A baby’s sleeping environment can cause SIDS.
This includes their:
- sleeping position and bedtime routine
- bedding and sleep environment
- bedsharing in hazardous circumstances
- exposure to tobacco smoke
Babies who die of SIDS are thought to have problems in the way they respond to these factors and how they regulate their heart rate, breathing and temperature.
The safest place for a baby to sleep, is a clear, flat sleep surface in the same room as the parents/ carers.
Although the cause of SIDS isn't fully understood, there are a number of things you can do to reduce the risk.
How to help reduce the risk of SIDS
Below is a list of things you can do to help prevent SIDS.
For at least the first six months your baby must be in the same room as you or their carer for every sleep (day and night).
Your baby must have a clear, flat sleep surface (no pillows, no quilts or duvets, no bumpers, no pods, nests or sleep positioners).
Place your baby to sleep on their back in the ‘feet to foot’ position (feet touching the bottom of the cot).
Use a light blanket firmly tucked no higher than the baby’s shoulders. Use a clean, firm, well-fitting mattress.
Breastfeed if you can, because it reduces the risk of sudden infant death. Put your baby back to sleep in their cot after any feeding.
If using a baby sleeping bag, make sure it is fitted with neck and armholes, and no hood
Do not:
- let your baby share a bed with anyone who has been smoking, drinking alcohol, taking drugs (including medication) or is feeling exhausted
- sleep with your baby on an armchair or sofa
- let your baby sleep alone in an adult bed
- cover your baby’s head
- allow anyone to smoke around your baby
- allow your baby to become overheated as they can’t control their own body temperature
- leave your baby sleeping in a car seat for long periods or when not travelling in the car
- put pillows, loose blankets, cot bumpers or sleep positioners in your baby’s cot
- sleep with your baby if they were born prematurely (before 37 weeks of pregnancy) or weighed under 2.5kg (5.5 pounds) when they were born
Co-sleeping/ bedsharing
Co-sleeping/ bedsharing refers to the practice of a parent or carer sharing a surface (a bed, sofa, armchair or other surface), with an infant for sleep, which can take place either intentionally or unintentionally.
Sharing a sleeping surface with an infant increases the potential risk of sudden infant death. The level of risk varies according to how the co-sleeping is arranged and individual factors relating to the infant and caregiver.
Tips for safer bedsharing
If you are going to bedshare with your baby, make sure:
- you put the baby on their back in a clear, flat sleep space
- pillows and adult bedding are away from the baby, to avoid obstructing breathing or over heating the baby
- you do not leave the baby alone in an adult bed
- the baby cannot be trapped, wedged or fall out of bed or get trapped between the mattress and wall
- other children or pets do not share the bed with the baby, as this may lead to suffocation or over-heating the baby
- Reduce the risk of sudden infant death syndrome
Seeking medical advice if your baby is unwell
Babies often have minor illnesses that you don't need to worry about.
Give your baby plenty of fluids to drink and don't let them get too hot.
If you're worried about your baby at any point, see your GP or contact GP out of hours service for advice.
Dial 999 for an ambulance if your baby:
- stops breathing or turns blue
- is struggling for breath
- is unconscious or seems unaware of what's going on
- won't wake up
- has a fit for the first time, even if they seem to recover
- Serious illness in children
Support services
If a baby dies suddenly and unexpectedly, there will need to be an investigation into how and why they died.
A post-mortem examination will usually be necessary, which can be very distressing for the family.
The police and healthcare professionals work closely to investigate unexpected infant deaths and make sure the family is supported. They should be able to put you in touch with local sources of help and support.
Many people find talking to others who have had similar experiences helps them to cope with their bereavement.
The Lullaby Trust provides advice and support for bereaved families.
More useful links
The information on this page has been adapted from original content from the NHS website.
For further information see terms and conditions.