Overview
Also known as ‘cot death’, sudden infant death syndrome (SIDS) describes the sudden and unexplained death of a child under the age of 1 year, most commonly while asleep. For it to be diagnosed, all other causes must be ruled out including a complete autopsy and review of the circumstances of death.
Pathophysiology
Its pathophysiology is unknown, however, the ‘Triple-Risk’ hypothesis has been proposed to explain 3 factors that lead to SIDS:
- A vulnerable infant with risk factors (e.g. prematurity)
- A critical period during the development of homeostatic control (e.g. cardiorespiratory mechanism regulation)
- An exogenous stressor (e.g. sleep environment, overheating, smoking)
It is thought that infants who die of SIDS have problems with responses involving breathing and heart rate to these exogenous stressors.
Epidemiology
- SIDS is one of the most common causes of death in infants aged <1 year in the UK
- SIDS is most common during the first 6 months of life
- Around 200 infants die suddenly and unexpectedly every year
Risk Factors
Major risk factors include:
- Prone sleeping – babies should sleep on their back
- Smoke exposure – increases the risk up to 5 times
- Prematurity – increases the risk up to 4 times
- Bed sharing or falling asleep with a baby on a sofa or armchair
- Soft bedding, head covering, and entanglement in bedding
- Hyperthermia (e.g. an overly warm baby)
Other risk factors:
- Male sex
- Alcohol and/or substance misuse
- Lower socioeconomic status
- Age <20 at first pregnancy
A combination of these risk factors is additive and increases the risk significantly.
Protective Factors
- Breastfeeding
- Dummies
- Room-sharing but not bed-sharing
- Babies should sleep in the parental bedroom but not the parental bed for the first 6 months of life
Minimising Risk
Overview
Although SIDS cannot be prevented entirely, its risk can be reduced by adjusting the above risk factors:
- Always place the baby on their back to sleep
- Keep the baby’s head uncovered
- Place the baby in the ‘feet to foot’ position with their feet touching the end of the cot to prevent them from sliding down and under the blanket
- Keep the cot clear of items, toys, and blankets
- Let the baby sleep in the same room (but not bed) as the parents for 6 months
- Maintain a comfortable room temperature (16-20 ºC)
- Use a firm, flat, waterproof mattress that is in good condition
- Avoid smoking and handling the baby after smoking
- Avoid co-sleeping on a chair or sofa
- If the person wants to co-sleep, avoid alcohol, drugs, sleeping tablets, and deep sleepers
- Do not share a bed with the baby if they had a low birth weight (<2.5 kg)
Support
The Lullaby Trust
The Lullaby Trust provides advice and support to affected families.
The Care of Next Infant (CONI) programme
The Care of Next Infant (CONI) programme provides support to parents who have lost an infant to SIDS during their next pregnancy and for up to the first 6 months of their baby’s life. This involves extra support with regular contact, training in basic life support, access to movement monitors, room thermometers etc.
