Infants who are swaddled, or wrapped tightly in a blanket, tend to sleep longer, cry for shorter periods and wake less frequently than babies left with their arms and legs free.
So the news that swaddling might also be a risk factor for sudden infant death syndrome (SIDS), hip dysplasia, overheating and other unwanted health problems must seem like a cruel, unfunny joke to sleep-deprived caregivers. But as more parents turn to swaddling to soothe their babies and help them sleep, health experts have started to take a closer look at it. What they are finding is concerning enough that a growing number of health professionals and medical organizations are now warning about the risks or recommending against the practice altogether.
"I believe that the data does suggest that [swaddling] increases risk," said Dr. Gideon Koren, director of the Motherisk program at Toronto's Hospital for Sick Children and one of the country's leading pediatric experts. "I have a problem with not allowing the kids to be the way nature wants them to be. Nature did not intend people to tie their legs for many hours."
Last week, the Registered Nurses' Association of Ontario published new sleep guidelines that highlight the fact some research has linked it to increased health problems. In 2012, the U.S. National Resource Center on Child Health & Safety, working with the American Academy of Pediatrics and the American Public Health Association, published a SIDS risk reduction document that warned of the potential negative consequences of swaddling. In 2011, Perinatal Services B.C. recommended against it, stating the potential risks are too high.
Many hospitals are also moving away from swaddling and few, if any, organizations endorse it.
But because swaddling hasn't been studied in extensive detail in numerous large studies, experts say it's hard to make a recommendation to parents. Dr. Koren said there is good evidence pointing to hip problems in babies who are swaddled too tightly. While some research has tied swaddling to SIDS and overheating, others are inconclusive or find no increase in harm.
The British Medical Journal study published in 2009 has convinced many that the issue needs to be looked at much more carefully in light of swaddling's growing popularity. Researchers interviewed parents of babies who had died as a result of SIDS. They recruited a control group of babies while their mothers were still pregnant and followed them for comparison purposes.
At the end of the four-year study, conducted in southwest England, the researchers found many well-known SIDS risk factors were more common in homes where babies had died, such as co-sleeping with a parent, caregivers who drank alcohol or took drugs shortly before the infant went to sleep and mothers who smoked during pregnancy. But they also found one factor they didn't anticipate: 24 per cent of the infants who died from SIDS had been swaddled before they were put to bed, compared to just 6 per cent of the control group.
Of those infants who died from SIDS while swaddled, 12 had been placed on their backs to sleep; four were on their sides; and three were on their stomachs.
Kim Williams, executive director of Perinatal Services B.C., said the study results shouldn't be ignored. While the exact link to SIDS is unclear, Williams pointed to the fact swaddled infants have a decreased "arousal response," may be likely to overheat and may inadvertently end up with a blanket covering his or her face, which are all risk factors.
She noted that swaddling appears to be a risk factor for SIDS, not the primary cause. Parents may like the idea of keeping their babies asleep longer, but that might not be in their best interests. Although infants often "startle" themselves awake with their arms while they are unswaddled, it's possible that might have a protective mechanism and squelching it could be harmful, she said.
"[Parents] also have to understand that it's better to be woken up a little more often with a baby that startles than having a baby that doesn't wake up ever," Williams said.
The warnings about swaddling have prompted advocates, such as Dr. Harvey Karp, author of the bestselling book The Happiest Baby on the Block, as well as many parents and caregivers, to voice their disagreement online and defend how well swaddling works to keep infants calm and able to sleep.
Many of them point to the fact swaddling has been used for centuries as proof that it works. Although it is an old practice, the prevalence in many developed countries dropped around the time of industrialization. In the 1990s, when researchers confirmed the link between babies placed on their stomachs to sleep and sudden infant death syndrome and began recommending infants be placed on their backs in their cribs, that began to shift. Swaddling experienced a resurgence as more parents looked for ways to keep their babies calm and settled on their backs.
But that still doesn't mean it's necessarily safe.
"The fact that it was used for many years by human culture is not proof of anything," Dr. Koren said. "People used to put mercury on budding teeth to avoid pain and it killed probably hundreds of kids, if not thousands."
Safe sleep options
Confused, exhausted parents might be wondering what the experts recommend instead of bundling their babies up like burritos. Here are some suggestions for safe sleep practices, gathered from safe sleep guidelines and interviews with experts:
- Place baby on his/her back in a crib, cradle or bassinet that meets current Canadian safety standards.
- No blankets, toys, bumpers or any other extraneous materials should be in the sleeping area.
- Make sure the mattress is firm. One rule of thumb: If you press your hand against the mattress and the imprint is visible, it’s too soft for a baby.
- A cold sleeping environment may increase the risk for SIDS. But instead of blankets, which can also increase risks, keep baby warm with a sleep sack that is the appropriate size. Alternatively, place a warm one-piece sleeper (or two) on the baby.
- Avoid smoking in the home and alcohol or drug use, as these all increase the risk of SIDS.