Each year in the United States, almost 2,500 seemingly healthy babies die of
sudden infant death syndrome, or
SIDS, before they're six months old.
A SIDS death happens while a baby is
asleep. It's the syndrome that is sometimes called "crib death."
Until recently, all science knew for sure about SIDS was that certain
environmental factors increased an infant's risk of suddenly dying, including exposure to alcohol and drugs while in the womb, premature birth, low birth weight, exposure to second-hand smoke after birth, and sleeping on his or her belly.
It's this last one that has seemed to play the greatest role in SIDS, and a highly publicized campaign about a decade ago got many parents to put their infants to sleep on their backs, which quickly decreased the SIDS rate by 40 to 50 percent.
There are many theories about why stomach-sleeping could cause an infant to stop breathing.
Perhaps the infant's jaw is compressed by the position of his or her head, in turn compressing the air pathway and making it difficult to breathe. Or perhaps an air-pocket forms in soft bedding, and the infant ends up breathing in his or her own air, leading to a build-up of carbon dioxide in the body.
But in both of these cases, the infant's
brain should send a signal to wake up and start crying because something's wrong. So maybe a pre-existing
anatomical factor prevents the brain from sending that signal.
Photo courtesy stock.xchange | Lakepeople
Researchers have been looking for proof of this anatomical risk factor for decades. Without it, SIDS is truly just a random, unpredictable death that leaves parents forever wondering if they did something wrong.
In an amazing turn for SIDS research, a group of scientists has published the first study that draws a conclusive link between anatomy and SIDS risk. It's in the
brain stem.
According to results published in November's Journal of the American Medical Association, it's possible that at least half of SIDS deaths are related to a defect in the way the brain stem handles a neurotransmitter called
serotonin.
Combined with an environmental risk factor such as stomach sleeping or a lung infection, an infant who has this inherent anatomical risk factor is more likely to experience SIDS than an infant whose brain stem processes serotonin normally.
If neurons in an infant's brain can't properly process serotonin, the brain can't effectively send the "Wake up!" signal when the infant experiences low oxygen levels.
Linear Mode
