Unsafe sleep environments can cause infant deaths

What the research found

Guidance consistently names the sleep environment as a key cause of deaths. A 2022 paediatric review of sleep-related infant deaths includes accidental suffocation and strangulation in bed among them. It describes sudden infant death as happening when a vulnerable baby meets a trigger, such as an unsafe sleeping environment, at a critical stage of development.

Reviews report that deaths fell dramatically after "Back to Sleep" campaigns began. A 2021 review said advice on back sleeping, avoiding smoke, avoiding too much bedding and avoiding specific cosleeping risks has greatly reduced sudden unexpected death in infancy worldwide. A 2023 review reported a drop of more than 50% since 1994 in the United States.

Australian guidance says babies are more likely to die suddenly and unexpectedly if they sleep on their tummies or sides. It lists soft, inclined or unstable surfaces such as couches, beanbags, prams, slings, swings, bouncers and car seats as unsafe. Hospital nursing guidance calls the sleep environment and sleep position the main modifiable risks.

What it doesn’t mean

• Much of the evidence is statistical association. A 2021 review noted that controlled studies of prevention are limited for ethical reasons. Sudden infant death syndrome has no single known cause, and some babies are more vulnerable than others.
• Death rates have stalled in some countries, and safe sleep advice has worked less well for more socially deprived families. Parents' choices are shaped by comfort, convenience and whether the advice feels credible. Supportive, practical help matters more than blame.
• If you are unsure how to set up a safe sleep space, or your baby has reflux or a medical need that affects sleep position, talk to your GP or child health nurse. Do not change position or use inclined products without that advice.