SIDS deaths have decreased nearly 50 percent since the American Academy of Pediatrics 1992 recommendation that babies be placed on their backs to sleep. But when infants reach 2 months of age, about 20 percent of parents in the United States place their babies on their stomachs to sleep because they say they appear more comfortable or to sleep better.
"That's also the time when babies have enough strength and are big enough that they can escape from the typical 'burrito' wrap style of swaddling," said Claudia M. Gerard, M.D., clinical instructor in pediatrics and lead author of the paper. "But in other cultures where swaddling is practiced, it's common to continue swaddling babies until they are much older."
According to Bradley T. Thach, M.D., professor of pediatrics and the study's senior author, swaddling is practiced almost universally in newborn hospital nurseries, and various traditional swaddling techniques are practiced in Turkey, Afghanistan and Albania. Swaddling may make a baby feel more secure and may limit the startle reflex, which may lead to full behavioral arousals. By allowing infants to stay asleep on their backs, parents would be less likely to intervene and change infants to the risky stomach-sleeping position.
This study examined the effect of swaddling on spontaneous arousals during sleep. Twenty-six healthy infants 3 weeks to 6 months old were alternately wrapped in a specially designed cotton spandex swaddle or not swaddled during daytime naps in a sleep laboratory. The cotton spandex swaddle did not restrict the baby's hip movement or breathing, but it did limit their breaking free of the swaddle.
After the infants fell asleep, the researchers evaluated rapid eye movement (REM) and quiet sleep (QS). These sleep states were determined by breathing patterns, eye movements and brain waves, and the number of sighs, startles and full arousals also were recorded. Infants who awoke during the study were lulled back to sleep by rocking, singing, feeding or given a pacifier.
The frequency of startles was decreased with swaddling during QS and REM sleep, and the frequency of behavioral arousals was decreased with swaddling during QS sleep. The duration of REM sleep almost doubled with swaddling.
"Now we have scientific evidence to support the age-old belief that swaddled infants sleep better than unswaddled infants," Gerard said. "It helps babies stay asleep and so may help parents keep their babies sleeping in the safer back position."
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