Many parents swaddle their babies to get them to sleep, but new guidelines from an influential nursing organization suggest it may not be the safest option.
Swaddling involves tightly wrapping an infant in a blanket in a way that restricts movement.
New sleep guidelines published this week by the Registered Nurses' Association of Ontario highlight that swaddling may pose some risks and that some research has linked it to a greater likelihood of sudden infant death syndrome, or SIDS.
Swaddling poses risks because babies can overheat, said Helen Tindale, a retired public health nurse who helped write the guidelines. The swaddling blanket can also come loose and cover the baby's face, which can pose serious risks.
"It's sort of a domino effect in terms of what the risk is," Tindale said.
The risks are especially high for babies that are placed on their stomachs to sleep, which Tindale said is becoming less common, but still important to warn parents about. Evidence shows babies placed on their backs to sleep have a lower overall risk of SIDS.
"There is currently no evidence on the 'safe way' to swaddle an infant, and hence caution regarding swaddling should be expressed with parents/caregivers," the guidelines say.
The guidelines suggest sleep sacks or wearable blankets can be used, as long as they are the appropriate size and are used according to the manufacturer's instructions.
Some studies have also suggested that swaddling can lead to a higher number of respiratory infections, put too much pressure on the lungs and affect a baby's lung capacity, and lead to hip problems if the blanket is wrapped too tightly. Some health experts also question whether keeping the movement of infants restricted is a good idea. Many parents point out that unswaddled babies can "startle" themselves awake because they are unable to control their hand movements. But the startle response may have a protective mechanism and stifling that could be dangerous, they say.
The concerns over swaddling prompted Minnesota to officially ban it in child-care centres. In Canada, few, if any, hospitals endorse swaddling, and many institutions are moving away from it. But individual nurses in some institutions swaddle newborns, and new parents will often follow their lead once they bring their baby home, Tindale said.
The new RNAO guidelines don't make a specific recommendation against swaddling because not enough evidence is available to make a declarative statement, Tindale said. In fact, most medical organizations have so far refrained from taking a stance.
Regardless, the guidelines will undoubtedly add fuel to the fierce debate over the merits of swaddling, considering it is widely used and many parents swear by it for soothing babies and putting them to sleep.
Swaddling is not a new concept. But with the rise of the "Back to Sleep" movement, which urges parents to place babies on their backs to sleep, as well as the publication of the bestselling book The Happiest Baby on the Block, which advocates swaddling, it has become increasingly popular among parents.
Babies should be put to sleep on their backs in a crib, cradle or bassinet that meets Canadian safety standards, according to the guidelines. Other than a mattress and fitted sheet, there should be nothing else in the sleep environment.
Extra blankets, toys, bumpers, sleep positioners and other products all add to the risk of suffocation, SIDS and other problems, the guidelines say.
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An earlier version of this article incorrectly said the guidelines of the Registered Nurses' Association of Ontario say sleep sacks and wearable blankets should not be used for babies. In fact, the guidelines say they may be used if they are the appropriate size and are used according to the manufacturer's instructions.