Like many new mothers, I have been vigilant about — or, as my hubby says, “totally obsessed with” — taking precautions against SIDS. So it’s heartening to hear researchers may have solved the mystery of what makes some babies vulnerable to sudden infant death syndrome, which kills more than 2,300 babies a year.
Turns out that, based on an autopsy study in the Journal of the American Medical Association, infants who died of SIDS had significantly lower levels of serotonin, a brain chemical that helps regulate breathing, temperature, sleeping, waking and other automatic functions, compared to babies who died of other causes.
Serotonin normally helps babies respond to high carbon-dioxide levels during sleep by helping them wake up and shift their head position to get fresh air, says senior author Hannah Kinney of Harvard Medical School and Children’s Hospital Boston.
When babies are placed face down, their exhaled carbon dioxide may pool in loose bedding, where it can be breathed back in, Kinney says.
Normally, babies sense high carbon-dioxide levels automatically and wake up, she says. Babies who don’t respond appropriately, however, may never wake up.
Doctors eventually hope to use their discovery to screen babies for serotonin problems and find a way to protect them, says co-author David Paterson, also of Harvard and Children’s Hospital. Those developments are still years away, he says.
If you’re wondering how this affects your baby, well, don’t throw away that silly-looking sleep sack just yet: The study confirms the importance of safe infant-sleeping practices, says Moon, who adds that babies who have normal serotonin levels could still die as a result of risky practices, such as loose bedding.
The Back to Sleep campaign, launched in 1994, helped to cut SIDS deaths in half; however, deaths have not declined further in the past decade.
Fingers crossed this finding leads to saving more lives — and that my daughter stops rolling over and sleeping with her FACE DOWN. Gah! (The sound I make every time I turn on the video monitor and see she has smushed her face into the mattress AGAIN.)