Swaddling – the practice of snugly wrapping an infant with a light cloth, with only the head exposed – mimics the warm, cozy environment of the mother's womb. It's reported to promote better sleep for babies.
But a new study in the journal Pediatrics links the practice to an increased risk of sudden infant death syndrome (SIDS).
Researchers looked at data from four observational studies of SIDS and swaddling that involved 2,519 infants, including 760 whose deaths were attributed to SIDS. Overall, 323 infants had been swaddled, including 133 who died of SIDS.
Overall, swaddling increased the risk for SIDS by about one-third.
Risks associated with swaddling
In February, my colleague Dustin Dwyer told us the importance of following the ABC's of infant safe sleep – babies should sleep Alone, on their Back, and in an empty Crib. Study researchers found that swaddling increases the risk of SIDS for older babies because they may roll onto their stomachs, leading to restricted breathing.
The risk is greatest in babies sleeping on their stomachs, less in those sleeping on their sides, and least in infants sleeping on their backs.
Swaddling can also increase the risk of overheating, as well as cause a baby to sleep too deeply, decreasing the infant's ability to arouse from sleep – both of which are SIDS risks.
Expert opinions of the practice
About 90% of infants in North America are swaddled during the first few months of life. Studies show that swaddled babies wake up less often, and sleep for longer stretches of time. It has also been found to improve neuromuscular development and reduce distress in preterm infants.
But expert opinions on whether or not to swaddle babies are split.
We know it increases sleep and reduces crying. Those are extremely important goals. Exhaustion and persistent crying are the chief triggers for marital conflict, postpartum depression, child abuse, overtreatment with medications, unsafe sleep practices and obesity.
Susan Guest, a clinical nurse specialist in maternal newborn care opposes the practice. She told The Globe and Mail:
To have them pinned down by a tight blanket doesn’t make a lot of sense. You need to know that, developmentally, they need to move, they need to be able to put their hand in their mouth.
Lead author Anna S. Pease says the results of the study should be interpreted with caution, because there are few studies of the subject, and the amount of good evidence is limited.
She told The Washington Post:
We already know that side and prone sleeping are unsafe for young babies, so the advice to place children on their backs for sleep is even more important when parents choose to swaddle them. We suggest that parents think about what age they should stop swaddling. Babies start to roll over between four and six months, and that point may be the best time to stop.
Here are some guidelines for safe swaddling from healthychildren.org:
- Place your baby on her back to sleep, every time you put her to sleep.
- Stopping swaddling around two months is recommended, but if you do it longer, monitor her to be sure she doesn’t roll over while swaddled.
- Don't have any loose blankets in your baby’s crib. A loose blanket, including a swaddling blanket that comes unwrapped, could cover your baby’s face and increase the risk of suffocation.
- Keep your baby’s crib free of bumper pads, soft bedding, wedges, toys, pillows and positioners.
- Swaddling can increase the chance your baby will overheat, so avoid letting your baby get too hot. The baby could be too hot if you notice sweating, damp hair, flushed cheeks, heat rash, and rapid breathing.
- Keep the baby’s head and face uncovered and don’t swaddle too tightly.
UPDATE: The headline of this story has been updated to better reflect the conclusion of the study.