New Research Identifies Why Infants Die From SIDS

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Sudden Infant Death Syndrome (SIDS)

Sudden infant death syndrome (SIDS), also known as “cot death”, occurs when a seemingly healthy baby’s sudden, unexpected, and unexplained death. Tragically, SIDS accounts for the premature death of around 200 babies a year in the UK, mostly during their sleep (NHS 2021).

Until now, the cause of SID has been unknown, and the best advice has been to sleep babies on their back, in the “feet to foot” position, head uncovered (NHS 2021). This uncertainty and the unexplained nature of such deaths have led many bereft parents to blame themselves, questioning whether they could have done something more? Did they contribute to their child’s death? As a result, many parents deal with intense feelings of guilt and shame, compounding the grief they are already experiencing.

Brand New Research Brings Hope

However, new ground-breaking research has revealed how and why many of these children die. As many in the medical community suspected (Scott, 2022), a defect in the brain which controls arousal from sleep prevents some babies from wakening or responding when they stop breathing (Harrington, Hadid & Waters, 2022).

The lead researcher, Dr Carmel Harrington, who lost a baby to SIDS 29 years ago, said, “Usually if a baby is confronted with a life-threatening situation, such as difficulty breathing during sleep because they’re on their tummies, they will arouse and cry out” (Connell & Vidal, 2022). This research shows that some babies don’t have this robust arousal response, and as a result, the babies simply stop breathing and pass away peacefully.

What causes sudden infant death syndrome?

Harrington and her team discovered that an enzyme, butyrylcholinesterase (BChE), which plays a significant role in the brain’s arousal mechanism, was lacking in babies who had died from SIDS. Discovering the role that BChE plays in SIDS paves the way to developing a screening test and targeted interventions, hopefully making SIDS a thing of the past.

Fittingly, the research was published on Mother’s Day (in Australia). Dr Harrington said, “This is the gift that I feel I got for Mother’s Day … [it] gives us a focus for our future research. So there’s quite a lot to be done. We need to understand the system better … We know what we have to do. It’s just actually getting the funding for it”. Let’s hope the funding is available as soon as possible.

If you need support

If you or someone close to you lost a child to SIDS (or any other cause), the effects stay with you for the rest of your life. If you feel it would be helpful to talk with someone, even if it happened a long time ago, do reach out. You can consult your GP, approach services such as The Lullaby Trust, or a counselling service like ours. Any loss can be traumatic, especially when it is sudden and unexplained. Talk to someone today.

If you would like to speak with someone, you can call 0151 329 3637, email or complete our online referral form.


Connell C. and Vidal, P. (2022). Sydney researchers find enzyme marker to help detect babies at higher risk of SIDS. ABC News.
Harrington C. T, Hafid, H. A. and Waters, K. A. (2022). Butyrylcholinesterase is a potential biomarker for Sudden Infant Death Syndrome. eBioMedicine.
NHS (2021) Sudden infant death syndrome (SIDS).
Scott, R. (2022) Researchers Pinpoint Reason Infants Die From SIDS. BioSpace

Some Common Questions Parents Might Ask

If you have lost a child to sudden infant death syndrome, you might be asking yourself questions such as:

  • why do babies die suddenly?
  • did my baby die?
  • what causes sudden death in infants?
  • was it my fault my baby died?
  • did my baby suffer?

Dr Harrington’s research suggests that some babies die because their bodies did not produce enough of an enzyme known as BChE. So, when they stopped breathing, the normal mechanism that would cause a baby to cry and awaken did not work. As a result, they would have died peacefully and painlessly.

How to avoid sudden infant death syndrome

It will be some time before a cot death screening test can be developed. Meanwhile, the NHS advises that you:

  • always place your baby on their back to sleep
  • place your baby in the “feet to foot” position
  • keep your baby’s head uncovered
  • let your baby sleep in a cot or Moses basket in the same room as you for the first 6 months
  • use a mattress that’s firm, flat, waterproof and in good condition
  • breastfeed your baby, if you can
  • make sure you use a sling or baby-carrier safely

Check out for further details.


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