Fact Check: Have Scientists Found the Cause of SIDS?

Sudden Infant Death Syndrome (SIDS) is a tragic medical phenomenon in which children younger than the age of one die with no known cause.

SIDS accounts for a number of the 3,400 sudden unexpected infant deaths each year in the United States according to the Centers for Disease Control and Prevention (CDC), yet researchers have struggled to discover what causes it to happen.

New research into the condition has attracted great attention this week.

The Claim

On May 6, 2022, a study was published in the journal eBioMedicine that aimed to investigate an underlying factor associated with SIDS in infants.

A report on the study by BioSpace, a digital hub for life science news and jobs, has been shared extensively on Twitter. One popular post, which had gained over 100,000 likes by Friday in less than 24 hours, read: "They found the cause of SIDS".

The BioSpace article states that the new study "confirmed not only how these infants die, but why."

It stated that researchers were able to confirm a theory that SIDS was caused by a defect in the part of the brain responsible for waking babies from sleep and controlling their breathing, based on the fact that the activity of a chemical called butyrylcholinesterase (BChE) was lower in babies who died of SIDS compared to living infants and those who died from other causes.

The Facts

It is true that researchers say they have found evidence that lower activity of the chemical BChE is associated with SIDS—an important step in preventing a condition that has left families bereaved without answers.

BChE is an enzyme that scientists do not fully understand, but studies suggest it may be involved in the transmission of nerve signals, according to MedlinePlus.

The new study does state that it may be involved in arousal systems of the central nervous system and it "may" be the case that a decrease in BChE activity could result in impaired response to an environmental challenge like CO2 rebreathing.

But care should be taken when declaring that scientists have found a "cause" of SIDS. This is not entirely correct.

What scientists have done is identify what may be a telltale sign, also called a "biochemical marker," in babies who died from SIDS, compared to those who did not.

This, the study states, "represents the possibility for the identification of infants at risk for SIDS infants prior to death and opens new avenues for future research into specific interventions."

In other words, it might help doctors tell which babies are at risk for SIDS and find out ways to help them.

But the researchers specifically note that their finding "may become a new disease category or 'cause' for those sudden deaths" only once borne out in future studies.

One limitation of the May 6 study is that while the scientists evaluated over 600 control samples, they do not know how common this abnormality is in the wider population. Again, this is something that could become clearer in future studies.

The Lullaby Trust, a British charity that raises awareness of SIDS, warned against reports that a cause of SIDS had been found on Friday.

"This study looks to identify a biomarker that could help detect babies more at risk of SIDS, and we urge caution when reporting on any research around 'causes' of SIDS," the charity said in a press release on May 13.

"Claims that a cause of SIDS has been found could give false hope to families whose baby has died suddenly and unexpectedly and may downplay the continued importance of the safer sleep advice.

"While research is underway, we urge all parents and carers with infants to continue following the evidence-based safer sleep advice to reduce the risk of SIDS occurring.

"This includes: always sleeping baby on their back in a clear sleep space on a flat, firm and waterproof mattress with no bulky bedding, pillows or cot bumpers. This advice has secured significant decreases in the number of babies dying of SIDS."

In addition, Peter Blair, professor of epidemiology and statistics at the Centre for Academic Child Health at the University of Bristol, told Newsweek:

"This is an interesting study and it would be good to know more about the categorization of death, background characteristics, and risk factors surrounding the last sleep for those SIDS infants who scored low for this marker.

"We need to be a little cautious as the numbers are small and this is a single study but it would obviously be a good idea to try and repeat this observational work.

"I don't think there is enough evidence presented yet to determine whether this is a biomarker for SIDS or associated with other risk factors, for example smoking, and certainly not enough evidence yet to describe this as causal."

The Ruling

Fact Check - Mostly False

Mostly False.

Researchers have made an important discovery that might in future enable doctors to identify babies at risk of SIDS and help them, that much is true. It could lead to finding a cause. But this is not the same as conclusively identifying a cause. More research is needed, as the study authors themselves make clear.


Holding baby's hand
A stock photo shows a mother holding a baby's hand. A new study has investigated a biological factor associated with Sudden Infant Death Syndrome. x-reflexnaja/Getty