Sudden infant death syndrome (SIDS) is the sudden and unexplained death of an infant who is younger than one year old. This sudden, unexpected death of an apparently well infant is diagnosed as SIDS if the death remains unexplained even after a thorough forensic autopsy, a detailed death scene investigation and the exploration of the medical history of the infant and his or her family.

Most SIDS deaths are associated with sleep and therefore are often referred to as cot deaths or crib deaths. Most babies die peacefully with no signs of suffering. Nine out of ten deaths from SIDS occur during the first six months.

Risk factors

The cause of SIDS is unknown. Although studies have identified risk factors for SIDS, such as putting infants to bed on their stomachs, there has been little understanding of the syndrome’s biological cause or potential causes. Boys tend to be more at risk of SIDS than girls. The risk is also greater for babies who are born prematurely, or who are born with a low birth weight.

Reducing the risk of SIDS

Although health care professionals don’t know what causes SIDS, they do recommend ways to reduce the risk. These include:

    • Do not smoke, drink or use medicine while pregnant. Infants of mothers who smoked during pregnancy are three times more likely to die of SIDS than those whose mothers were smoke-free
    • Receive early and regular prenatal care
    • Breastfeed, if possible. There is some evidence that breastfeeding may help decrease the incidence of SIDS
    • Place babies on their backs to sleep every time, even for short naps. “Tummy time” is for when babies are awake and someone is watching
    • Use a firm sleep surface, such as a cot mattress covered with a fitted sheet
    • Keep soft objects and loose bedding (e.g. pillows) away from the sleep area
    • Keep the room at a comfortable temperature
    • Put your baby to sleep with a dummy during the first year of life, if possible. Pacifiers have been linked with lower risk of SIDS
    • While infants can be brought into a parent’s bed for nursing, parents should return infants to their cots for sleeping
    • Do not expose your baby to secondhand smoke; it doubles an infant’s risk of SIDS
    • Make sure your baby has regular checkups

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