Death from Swaddling...

Death From Swaddling

Can Swaddling Be Made Safer?

Laura A. Stokowski, RN, MS

March 14, 2014

Infant Deaths and Injuries Associated With Wearable Blankets, Swaddle Wraps, and Swaddling

McDonnell E, Moon RY

J Pediatr. 2014 Jan 30. 

Rebirth of an Ancient Tradition

A tightly swaddled baby, asleep in a crib, paints a very peaceful picture. Swaddling, an ancient childcare practice used to keep babies content, warm, and asleep, is as popular as ever. Swaddling inhibits movement and calms fussy babies, making it easier to settle babies to sleep -- and keep them asleep -- in the supine position. Swaddling also obviates the need for blankets, which are unsafe in the sleeping environment of infants. Despite these benefits, swaddling has not been recommended as a strategy for the prevention of sudden infant death syndrome (SIDS),[1] and the potential risks associated with swaddling have long been recognized.[2]

The simplest way to swaddle a baby is with a standard cotton blanket, but simple has been improved upon, naturally, by the upscale baby market. Parents can now purchase wearable blankets and swaddle wraps that make the swaddling process easier. A "wearable blanket" is a product made of soft fabric or fleece with openings for head and arms, and a zipper down the front. The bottom may or may not have leg openings. A "swaddle wrap" is a swaddling blanket with "pockets" for the infant's legs and arms and Velcro® to keep the arm panels in place when they are wrapped around the infant. Some products are a combination of a wearable blanket with Velcro panels to swaddle the infant's upper torso. Millions of such products have now been sold, but very little is known about whether they make the infant sleep environment more, or less, safe.

A Retrospective Study of Swaddling Deaths and Injuries

A recent study examined swaddling incidents reported to a voluntary reporting database, the Consumer Product Safety Commission (CPSC), from 2004 to 2011. McDonnell and Moon collected demographic information and data on infant position, type and mechanism of injury or potential injury, cause of death when applicable, and presence of known SIDS risk factors (such as smoke exposure, presence of soft bedding, or bed sharing) in swaddling incidents involving 36 infants ranging in age from 3 days to 15 months, including:

 5 cases involving wearable blankets (1 death, 2 injuries, 2 potential injuries);

 18 cases involving swaddle wraps (8 deaths and 10 potential injuries);

 1 death involving an unspecified product (either swaddle wrap or wearable blanket); and

 12 deaths involving swaddling in ordinary blankets.

In the cases of infant deaths involving wearable blankets or swaddle wraps, 7 out of 10 infants were placed to sleep supine, but the swaddled infants rolled to the prone position (1 reportedly at 5 weeks of age) and death was attributed to positional asphyxia. Among infants who were swaddled in standard blankets, 6 died in a similar fashion. In some cases involving swaddling blankets or standard blankets, parts of the blanket were found covering the dead infant's nose and mouth. Other risk factors were believed to contribute to infant deaths, including the use of soft bedding and hyperthermia from overbundling in an excessively warm environment. Of the total 22 deaths in the study, only 1 involved no sleep environment risks. The investigators documented many other safe-sleep infractions in the reported cases, such as the use of soft bedding (blankets, pillows), bumper pads, comforters, stuffed animals, bed sharing with adults, and secondhand smoke.

The 2 injuries that were reported involved older infants (9 and 15 months) whose teeth became snagged on the zippers of wearable blankets, resulting in accidental tooth extraction. Ten reports described potential injury associated with swaddle wraps when part of the swaddle wrap became wrapped around the infant's face and/or neck. The infant's arms and/or legs came out of the swaddle wrap, and the wrap was pushed up to the face and/or neck, posing the risk for asphyxiation, although the infant was not harmed.


As acknowledged by McDonnell and Moon, considering that millions of babies have probably been swaddled at some point during the years studied, 36 is not a lot of incidents. However, given that CPSC is a voluntary database and without a firm denominator, we have no way of knowing the true rate of injury or death associated with the use of swaddling practices or products. Our aim, of course, is zero.

Even without denominators, it is clear from this report that swaddling in ordinary blankets is not a safe practice beyond the immediate newborn period. An ordinary blanket has nothing to keep it securely in place, and with very little movement at all, it ends up becoming a loose piece of bedding in the infant's sleeping environment -- the very thing we advise against when we teach parents about safe sleep.

Swaddling is almost universally practiced in birth hospitals, primarily as a thermoregulatory measure. Parents are taught to never place loose blankets on top of their infants, and because hospitals aren't able to supply warm, fleecy infant sleepers (baby pajamas) for newborn infants, babies are dressed in cotton T-shirts and wrapped in standard, hospital-issued blankets to keep them warm while they sleep in their bassinets. Many new parents simply model this behavior when they take their newborns home from the hospital, substituting a better-quality blanket or a product purchased for the purpose of swaddling.

Strictly speaking, a newborn infant doesn't need to be swaddled to be put down to sleep. Swaddling is a parenting choice, like breastfeeding or using a pacifier. The infant can be dressed in a sleeper of an appropriate fabric weight for the season and the temperature of the home, and placed supine in a crib with no other wrapping at all. However, some studies have shown that swaddling prevents the supine infant from waking spontaneously by minimizing arousals during rapid eye movement (REM) sleep.[3,4] In other words, the swaddled infant doesn't wake him or herself with jerking "startle" movements of the arms or legs that often happen during REM sleep. This, along with less overall crying, is why many people swaddle a healthy supine sleeping infant during sleep.

Not All They Are Wrapped Up to Be?

Still, there is no denying the appeal of swaddling in contemporary society. Last year, a huge debate arose about swaddling when, for safety reasons, 3 states instituted a ban on swaddling in daycare centers.[5] Many people became very upset because they did not believe that such a step was warranted, and thought that their parenting rights were being infringed upon.

The problem is that, although not believed to be common, there are potential harms and dangers associated with swaddling, and people should be aware of them. Swaddling too tightly or with the legs extended and adducted can cause developmental dysplasia of the hips.[6] Swaddling can also result in hyperthermia when the wearable blanket or swaddling blanket is added to the clothing and hat that the infant is already wearing. Tight swaddling can compromise the lungs and has been shown to increase the respiratory rate, presumably to compensate for a reduction in functional residual capacity.[7] Although this is unlikely to affect a healthy term infant, it could be detrimental to an infant with a chronic respiratory condition or respiratory infection.

Although some have argued that swaddling lowers the risk for accidental death by immobilizing infants in the supine position,[8] swaddling is also associated with a significantly increased risk for accidental death if, as in many of the cases reported to CPSC, the infant is placed to sleep in the prone position while swaddled, or rolls into the prone position from either a supine or side-lying position. Swaddled, prone-lying infants are unable to use their arms or upper bodies to push themselves off of the mattress or to change their head and body position if they find themselves in an asphyxiating situation. The infant essentially suffocates, trapped face-down in the mattress. Many of the infants in this study were older than 4 months of age and were still being swaddled when they were put down to sleep. Because it can't be predicted with certainty when the gross motor skill of rolling from supine to prone will begin to emerge, many of these infants were too old to be swaddled in this manner.

Safe Swaddled Sleep

The study by McDonnell and Moon illustrates a couple of very important points. First, it shows how very far we are from achieving the kind of consistent, safe sleep environments for infants that we hoped would exist by now in homes across the country, with or without swaddling. Second, it shows that swaddling has introduced another variable to this environment that poses risks for at least some infants, although we might not yet have a handle on who those infants are. Despite criticism from those who believe that swaddling is no riskier than hugging and singing lullabies, we have to treat swaddling with the caution that it has shown it deserves, as another element in the already overcrowded message about safe sleep that healthcare providers must repeat to all new parents before they leave the hospital and again at every well-baby visit.

Considering the resurging popularity of swaddling, we will best serve parents by making sure that they use swaddling as safely as we know how, within the context of a safe sleep environment. This includes the following:

 Talk about swaddling and the alternatives to swaddling (eg, standard infant sleepers/clothing of appropriate weight for the ambient temperature that can be worn without the need for additional wrapping).

 Teach appropriate layering and thermoregulation; some parents believe that infants need more layers than they really do. Although we don't generally recommend taking an axillary temperature unless the baby appears ill, it might not be a bad idea if you are concerned that the family has a tendency to overbundle the infant.

 Have parents bring in what they plan to use at home for swaddling, and teach them how to swaddle properly to prevent damage to hips.

 Discuss when to discontinue swaddling. Although some physicians disagree about how long swaddling can safely continue, Dr. Rachel Moon, who is also lead author of the American Academy of Pediatrics Safe Sleep guidelines[1] and chair of the Task Force on SIDS, believes that babies should not be swaddled past 2 months of age.[5]

 If parents are taking their infant to day care or a babysitter, they need to ensure that these caregivers know how to swaddle properly (if swaddling is permitted at all) and follow all other rules of safe sleep. If parents have stopped swaddling their infant, caregivers should be instructed to stop swaddling as well.

 If parents continue to use a wearable blanket or wrap beyond the recommended age, they must carefully watch for signs that the infant is close to being able to roll over, in either direction. They should observe the infant's movements during supine and prone play; an infant who seems close to rolling in either direction (a "partial roll") or who can roll from prone to supine should no longer be swaddled using any method. Even if the infant can't accomplish a roll by him- or herself, the movements that the infant makes in attempting to roll could unravel the swaddling wrap or blanket.

 Reinforce the other elements of the safe sleep environment.

Parents should be aware that injuries, including deaths, have occurred with swaddling, including some incidents where no improper use of swaddling or unsafe sleep practice could be identified. An insecurely applied swaddle wrap or wearable blanket can unravel during sleep, and (as demonstrated by the infant deaths in this study), can end up obstructing the infant's airway or even strangling the infant. The plain truth is that the safety of these products, even when used as correctly as humanly possible, has not been established, and people who use them do so at their own risk.