By: T. Berry Brazelton, M.D., and Joshua Sparrow, M.D.

Q. Are there any negative side effects to swaddling with the baby’s arms down along the sides of the body?

A. Swaddling – snugly wrapping your baby in a blanket – is an age-old, nearly universal strategy for comforting young infants. It seems to have fallen out of favor a few hundred years ago in many cultures, but not in the Middle East, and not among many Native American tribes.

Many Native American peoples have long used cradle boards – a flat board to which cloth or animal skin was attached – to keep their babies snug, warm, easily carried and out of harm’s way.

Many cradle boards have “bumpers” at the top ingeniously extending beyond the baby’s head so that it is fully protected. In some tribes they were positioned at a gentle angle for feeding or upright so that the babies in them could watch other family members at work and begin to learn about their world.

In fact, we would expect that these babies would be able to muster up more energy for visual learning since the cradle boards kept their little bodies at ease and under control.

Recently, swaddling seems to have been making a comeback, in the United States, the United Kingdom and other European countries. This may be because now that we understand the advantages of positioning babies on their backs for sleep to decrease the risk of Sudden Infant Death Syndrome, we need a way to help babies fall asleep and stay asleep in that less comfortable position.

Swaddling has many obvious benefits, helping to keep babies warm, calm and comfortable. Swaddled babies will rouse less and sleep longer. At the beginning of life, the snugly fastened wraps recreate the womb’s supportive fit, cutting down on a newborn’s startles and jerks – motor reflexes that otherwise make the baby feel uncomfortable and often start to cry.

Modern science has established numerous other benefits of swaddling, and special circumstances in which it is particularly helpful. One study has even shown that premature infants may have improved neuromuscular development when regularly swaddled.

But you ask about negative effects. A recent study showed that Hopi infants raised in cradle boards did not start walking any later than those raised without them. There are, though, studies that link swaddling to early hip problems (hip dysplasia and dislocation), but the risk may be the result of the specific position of the legs under the swaddles. These studies suggest that it is important to avoid fully extending the legs, or rotating hips outward when swaddling a baby. Swaddling babies so that their hips and knees are bent and with enough slack to allow movement appears to be safer for their hips.

In warm climates or over-heated buildings, care must be taken not to let an infant’s body temperature rise dangerously high when tightly wrapped. There are a few studies that have found that babies swaddled from head to toe all day long for several months may be more likely to be deficient in Vitamin D, presumably because swaddling cuts down on their exposure to sunlight, which is needed to activate Vitamin D.

Other studies suggest that very tight swaddling may slightly increase a baby’s vulnerability to respiratory infections, perhaps because it limits the normal expansion of chest and lungs. These studies seem to suggest avoiding prolonged swaddling, swaddling from head to toe, and overly tight swaddling. This shouldn’t interfere with the containment and comfort that swaddling still can offer, and many pediatricians feel that swaddling a baby for 12 to 20 hours a day in the first weeks is perfectly fine, and that it can be gradually decreased after a month or two depending on a baby’s comfort without it.

As for swaddling the arms alongside the body, we have not found any studies to suggest that this is a problem. However, it is important to leave the arms free often enough that babies can discover their fingers and thumbs, so that they can learn to use them to comfort themselves by fondling the soft edges of their blankets, their own soft cheeks, or by sucking on them.

Swaddled or not, it is critical to position babies on their backs when asleep, or likely to fall asleep so that they are at less risk for SIDS. It is also critical that when awake all babies are given plenty of time to play while on their tummies so that they can strengthen their arm, shoulder and back muscles. This has become a major concern for babies who spend much of their awake time in car seat-like baby carriers. We did once encounter an 8-month-old with delayed motor milestones, not yet sitting on his own. He had been a fussy baby, and his mother had religiously adhered to an intensive regimen of swaddling that some pediatricians recommend for such babies. Swaddling does seem to reduce crying and can even soothe pain. We had no way of knowing whether he’d had too much swaddling for his own good, but we’ll always wonder.

Responses to questions are not intended to constitute or to take the place of medical or psychiatric evaluation, diagnosis or treatment. If you have a question about your child’s health or well-being, consult your child’s health-care provider.

Before Dr. Brazelton’s passing in 2018, he was the founder and director of the Brazelton Touchpoints Project, which promotes and supports community initiatives that are collaborative, strength-based, prevention-focused sources of support for families raising children in our increasingly stressful world. Dr. Sparrow, a child psychiatrist, is now the director of the Brazelton Touchpoints Center.  Learn more about the Center at

Reprinted with permission from the authors.