Meanwhile, they're not making new recommendations about sleep positions. The study by Kevin Pereira, MD, and colleagues appears in the Archives of Otolaryngology -- Head & Neck Surgery.
Half a million American children have obstructive sleep apnea, note Pereira and colleagues.
Pereira works at the University of Texas Health Science Center at Houston. He's on staff in the center's department of otolaryngology -- head and neck surgery.
Sleep Apnea Study
At the sleep center, the children's sleep positions were tracked. More respiratory problems were seen when the children slept on their backs, the study shows.
Toddlers Sleep Differently
Other work has shown that adults with sleep apnea breathe better when they're not sleeping on their backs. Past studies of children have had mixed results and rarely included very young children, the researchers note.
"Our observations suggest that toddlers have sleep characteristics that are different from those of older children," they write.
"Sleep studies may have to take these age-group differences into consideration before declaring the findings adequate for interpretation," they continue.
Few Infants Studied
Very few kids in Pereira's study were infants. So the researchers aren't countering advice to put infants to sleep on their backs.
"We cannot comment on the relevance of our findings to the practice of putting infants to sleep on their backs to avoid sudden infant death syndrome," Pereira's team writes.
Sudden infant death syndrome, or SIDS, is the sudden and unexplained death of an infant under 1 year of age. Its cause isn't known.
Put infants to sleep on their backs to reduce SIDS risk, recommends the American Academy of Pediatrics.
Check with your baby's doctor if you have any questions or concerns about your baby's sleep positions or breathing.