All these things can reduce your baby’s chances of SIDS, but without knowing its cause, we have not yet been able to completely prevent SIDS. Now, researchers have identified a biomarker that could help us understand the cause of SIDS and perhaps prevent babies from dying in their sleep.
What the Researchers Found
Researchers in Australia found that babies who died from SIDS had significantly lower levels of the enzyme butyrylcholinesterase (BChE) than babies who died of other causes. BChE is an enzyme from the cholinergic system, which regulates aspects of brain function, including arousal. Lowered arousal is thought to be a factor in SIDS, so it is telling that the babies who died of SIDS had lower levels of an enzyme that regulates arousal. Another very important part of this study was that the enzyme was measured in blood that was taken before the babies’ deaths. This means that with further research, it may be possible to identify a SIDS biomarker while a baby is still alive.
Details of the Study
The researchers looked at blood samples taken at birth. If you have ever seen your baby get a finger prick at one of their well-checks, this is where they got their data. Using blood samples of over 600 babies, the research team separated those babies who died during the first year of life into two groups: SIDS deaths and non-SIDS deaths. They found that those babies who died of SIDS had significantly lower levels of BChE. This research is exciting but it remains speculative for now. One of the study’s major limitations was the age of the samples. Blood samples are only known to be stable over 22 weeks and these were two years old. The total number of samples was also too small to draw any definite conclusions. The researchers also did not have access to any autopsies. These limitations mean that while the research is promising, there is still more to learn to fully understand SIDS and how to prevent it.
The Connection Between Arousal and SIDS
We know that lowered arousal is related to why babies die of SIDS. “Arousal from sleep is an important protective response to life-threatening stimuli, such as overheating, airway obstruction, lack of oxygen, or inhaling too much exhaled C02,” says Sarah Mitchell, DC, a baby sleep expert and consultant, author of “The Helping Babies Sleep Method,” and owner of Helping Babies Sleep. “A child needs to be able to wake up and call for help.” For this reason, many of the protective measures that parents can take against SIDS help to keep babies in a lighter stage of sleep, such as using a pacifier and breastfeeding on-demand. “Frequent wakings allow for less time to be spent overall in deep sleep which is harder to wake up from,” notes Dr. Mitchell. This explains why a deficiency in an enzyme that helps to regulate arousal could be a potential biomarker for SIDS. “Babies are born with a natural reflex built in that protects them if they stop breathing,” says Heather Wallace, a certified pediatric sleep consultant, certified postpartum doula, and the owner of BraveHeart Sleep Training and Postpartum Doula Consulting. “If this mechanism is not working properly, the baby may not wake up if they are in danger, such as if they are in a position that compromises their airway or if their breathing is blocked by something external.” A baby that wakes up can adjust its position or cry out for help. Room-sharing has been found to be a protective measure against SIDS, presumably because parents can respond more quickly if the baby is in distress but not yet strong to move themselves.
What’s Next?
At this point, we cannot say that we have found the cause of SIDS or that we can put an end to this heartbreaking syndrome. What we do have is hope for the future. This new study suggests that with further research, we may be able to pinpoint the cause of SIDS and create interventions to prevent it. Refraining from smoking during and after pregnancy, breastfeeding your baby, and sharing a room but not a bed for at least 6 months and ideally a year have also been found to protect against SIDS.
