Until recently, swaddling was a matter of course. Each mother left the hospital with the skills of swaddling a baby and could not imagine how it could be otherwise. At the same time, the children lay like logs and slept soundly, not rousing themselves with their hands.

Nowadays, swaddling is not so common. However, there are those who use it. There are even those who get used to it so hard that they cannot get away from it in the future.

Swaddling refers to wrapping the baby tightly or loosely in a cloth (usually a light diaper) with the head open. With tight swaddling, the child really lies like a log and cannot move either his arms or legs. With free swaddling, some freedom of movement still remains under the diaper.

There is not a lot of qualitative research on the topic of swaddling, as there are many nuances. In particular, there are still no precise, substantiated recommendations on how exactly to swaddle, and therefore different swaddling options may be used in the same study. Let’s take a closer look at some of the facts and hypotheses put forward in relation to swaddling.

Can swaddling increase your risk of sudden infant death (SIDS)?

Anna S. Pease et al., 2016 pooled data from four observational studies that examined the relationship of SIDS and swaddling, which included 760 SIDS cases and 1759 cases for comparison.

It was found that swaddling combined with sleeping on the stomach or on the side doubled the risk of SIDS compared to babies who were not swaddled. It is noteworthy that even with the combination of swaddling and sleeping on the back, there was a small but significant risk of developing SIDS.

Anne-Louise Ponsonby et al., 1993 also found that swaddling significantly increased the risk associated with sleeping on the stomach. At the same time, the authors suggest that swaddling as a condition providing stability of position may be useful for babies who sleep on their backs. In support of their hypothesis, they cite the work of Beal S, Porter C., 1991, who noticed that in countries like China, where babies are swaddled but put to sleep on their backs, SIDS is rare. That being said, swaddling can increase the risks for babies who are trying or are already able to roll over.

Anna S. Pease et al., 2016 also note that the risk of SIDS increases with age. The authors associate this precisely with the fact that a child at an older age can roll over on his stomach or simply undress and cover himself with the same diaper in which he was wrapped. In this regard, the researchers proposed to establish the age after which swaddling should be stopped. It is assumed that this is about 4-6 months of age, since it is at this time that the babies begin to roll over. McDonnell E, Moon RY, 2014, in their retrospective review of incidents reported to the Consumer Product Safety Commission, came to the same conclusion.

Due to the risk of rolling to a prone position, the Dutch guidance document recommends not starting swaddling after the fourth month, and also to stop swaddling the baby as soon as he signals that he is trying to roll over, and in any case, stop swaddling before the sixth month (after this age babies can roll over). How to carefully avoid swaddling — we will consider in the next article .

Also Anna S. Pease et al., 2016 suggest that an increase in the risk of SIDS is possible due to the fact that swaddled infants have fewer spontaneous awakenings from sleep, and the duration of sleep increases. These signs indicate decreased excitability. In this state, it may be more difficult for a child to wake up in a life-threatening situation.

In general, sleeping on your back is currently considered the safest in terms of the risk of SIDS. With the use of swaddling, this sleeping position becomes even more significant. It is also important to stop swaddling from the moment the baby starts attempting to flip.

It should be noted that there is currently no convincing evidence of a connection between swaddling and SIDS. Most studies have other risk factors that may also increase the risks of SIDS. In addition, the researchers themselves often note that there were different swaddling techniques. It is possible that tight and loose swaddling (which also has several variations) can have different effects.

Does the risk of overheating increase when changing?

Anne-Louise Ponsonby et al., 1993 found that swaddling and using natural fiber mattresses can reduce heat loss in infants, which can actually lead to overheating under certain circumstances. Anna S. Pease et al., 2016 confirm that there really is a risk of hyperthermia (in fact, overheating), especially with the wrong swaddling technique.

In this regard, it is important to consider some factors:

— The child should be dressed in appropriate clothes, and sometimes be without them at all (depending on the air temperature in the room where the child sleeps).

— The child’s head must be open. In babies, excess heat is released mainly through the head and limbs. Due to the fact that the limbs are usually closed during swaddling, it is important to leave at least the head.

— We put the child on the back only. Belly posture is an additional contributing factor to overheating.

— Diseases accompanied by fever can increase the generation of heat. Since swaddling prevents him from going out, it is better to stop him during the illness.

— Sharing sleep promotes better heat transfer. In combination with swaddling, this is an additional risk of overheating, so swaddling while sleeping is undesirable.

— Swaddling tightly can increase the risk of overheating, so it is important that 2-3 fingers can fit between the baby’s breast and the diaper.

Does swaddling increase your risk of dysplasia?

Traditional tight swaddling with outstretched legs can indeed contribute to subluxation and dislocation of the hip (You Zhou et al., 2020, Nelson AM., 2017). For this reason, the International Hip Dysplasia Institute recommends swaddling with slight bending of the knees and extension of the legs to the sides to promote proper development of the hip joint. More details about this type of swaddling will be in the next article .

How does swaddling affect baby’s development?

Ksenia Bystrova et al., 2009 found that swaddling a baby reduces the mother’s response to him, her ability to interact positively and effectively with the baby, and to establish connection and reciprocity in a dyad.

Nils J Bergman, 2016 suggests that swaddling can be stressful for the infant as it results in separation from the mother, which in turn increases autonomic arousal. Babies should never sleep alone.

Indeed, sleeping alone, when the baby is crying, and they do not react to his cry, can lead to stress with the release of the corresponding hormones. And with prolonged, frequent exposure to these hormones on the child’s body, including, the processes of its development can slow down.

At the same time, the Netherlands, a country with low SIDS, advises encouraging swaddling to reduce excessive crying.

Anna S. Pease et al., 2016 also state that swaddling results in more restful sleep, a decrease in spontaneous arousal, and some reduction in excessive crying in infants up to 7 weeks of age. Additional benefits were observed for some groups of babies, in particular:

— improvement of neuromuscular development in children with very low birth weight;

— reduction of physiological and behavioral distress in babies born prematurely;

— Better sleep and faster sedation in infants with neonatal withdrawal symptoms.

Several studies have shown that swaddling is effective in calming and reducing pain in infants (Shu SH et al., 2014, Erkut Z, Yildiz S, 2017). In a 2017 comprehensive review of the risks and benefits of swaddling healthy babies, Nelson AM., 2017 concluded that swaddling is indeed calming and conducive to falling asleep, but is equal or less effective in treating pain than other non-pharmacological methods.

Why is there such a contradiction? Perhaps in the first case, where swaddling was viewed as stress, it was about tight swaddling. Indeed, not all children agree to lie like logs. In addition, when the mother swaddles the baby and puts him to sleep in a crib far away from herself (perhaps even in another room), this can affect the care of the baby not for the better.

At the same time, free swaddling, when the diaper hugs the baby, but leaves him some freedom of action, can remind the baby of the mother’s womb, where he felt good, calm and safe. It is the feeling of security that gives the child peace of mind. If at the same time the mother is not far away, she is able to respond to the child’s calls — as a rule, there is no stress.

In addition to stress hormones, the quality of sleep also affects the development of a child’s brain. It is known that the brain develops in a state of REM sleep (Melissa Bartick et al., 2018, John Peever and Patrick M. Fuller, 2018, Madeleine M. Grigg-Damberger, 2016). REM sleep may also play a role in protein synthesis, learning and memorization (Levental M et al., 1975, Dahl RE, 1996). Lack of REM sleep can be correlated with both hyperactivity and depression (Luisada PV, 1969, Patchev V et al., 1991).

That is why such a superficial sleep normally prevails in a child during the first months of life. At the same time, children wake up easily from REM sleep, so frequent waking up is not uncommon for a baby. In turn, swaddling, as mentioned above, reduces the number of spontaneous awakenings and lengthens the duration of sleep.

It seems quite logical that this should be due to deeper sleep, because it is during this phase that there are fewer awakenings. By no means, Claudia M. Gerard et al., 2002 found that swaddling is associated with an increase in REM sleep, not slow sleep. The authors speculate that this is due to a decrease in arousal and, as a result, a faster return to sleep. What is the reason for the decrease in arousal itself is not very clear. Most likely, with a decrease in motor activity. It is worth noting that this study used free swaddling where the children were able to move somewhat, but were unable to raise their arms.

What other aspects of swaddling are worth noting?

Laura Fletcher et al., 2018 note that some studies have found correlations between swaddling and respiratory infections (particularly pneumonia), rickets, postpartum weight gain, but none have provided conclusive evidence.

Claudia M. Gerard et al., 2002 found that some children do not sleep well on their backs, and this position is considered optimal for reducing the risk of SIDS. Despite the danger of sleeping on their stomachs, some parents walked towards the children and laid them in this position, because this way the excitability decreases, and the babies sleep better, less often wake up. It turned out that sleeping on your back, combined with free swaddling, helps a lot in this situation.

Free swaddling can also be used while awake to comfort your baby, or when dealing with restless breast behavior. The American Academy of Pediatrics (AAP) and the American Association of Public Health do not prohibit or recommend free swaddling because there is no conclusive evidence of the usefulness or harmfulness of this method. That being said, of course, the AAP only considers loose swaddling. Swaddling tightly is not recommended given the current evidence of its risks. Fortunately, Laura Fletcher et al., 2018 found that this type of swaddling is practically not used anymore.