Researchers believe they may have found the cause behind sudden infant death syndrome.
SIDS accounts for more than one-third of sudden, unexpected deaths among infants each year in the U.S.
It impacts infants under a year old and usually happens when the child is sleeping.
Doctors have suspected that SIDS may be caused by a defect in the part of the brain that controls arousal from sleeping and breathing, according to the study published on Biospace.
That means if a child stopped breathing while they slept, the brain defect would prevent them from waking up.
Researchers at The Children's Hospital Westmead in Sydney compared blood samples from newborns who died from SIDS and from healthy babies,
They found that babies who died of SIDS had lower activity of the enzyme butyrylcholinesterase (BChE), than healthy babies.
BChE plays a major role in the brain’s arousal pathway, researchers said.
Parents have been previously advised that they should lay babies on their backs, keep toys and blankets out of the crib and not letting babies overheat as ways to prevent SIDS.
Now researchers say that while these safe sleep practices are important, they may not necessarily prevent SIDS-related deaths.
Researchers said the new findings will open “new avenues for future research into specific interventions.”