Swaddling is the age-old practice of wrapping a baby snugly in a light blanket for warmth and security — much like their former living quarters, AKA mama’s womb. While the benefits of putting a baby to bed in a burrito-style wrap have been widely documented, what many moms don’t realize is that if not done properly, swaddling can actually do harm. To ensure that we are doing this whole swaddling business safely, we tapped Emily Dodwell, MD MPH, — Pediatric Orthopedic Surgeon, Hospital for Special Surgery for her expert advice.

StrollerTraffic: We know that swaddling helps babies feel secure – mimicking the feeling of being snug in mom’s womb – and we often hear about the benefits of swaddling. Are there any dangers?

Dr. Emily Dodwell: Infant swaddling entails wrapping an infant in a light cloth or blanket to provide a kind of cocoon. Swaddling has been shown to reduce crying and promote sleep but if not done properly, it could harm an infant’s hips.

Wrapping the blanket too tightly about the legs puts a baby at risk of developing a condition known as hip dysplasia, in which the hips do not grow properly. The condition is often referred to as “developmental dysplasia of the hip” or DDH.

Think of the hip as a “ball-and-socket” joint. In a normal hip, the ball at the top part of the thigh bone fits firmly into the socket, which is part of the pelvis. When a baby develops hip dysplasia, it can range from mild to severe. The ball may be loose in the socket or it may partially come out of the socket. Sometimes it dislocates out of the socket completely.

Untreated hip dysplasia can cause serious problems later in life. With the more severe form, which is a complete dislocation of the hip, children could develop an abnormal way of walking, experience hip or back pain and potentially need a hip replacement at an early age. Even those with untreated mild dysplasia may be more likely to develop arthritis and hip pain in their teens or early adulthood, and they may need surgery.

StrollerTraffic: What is the proper technique for swaddling a baby?

Dr. Emily Dodwell: Parents and caregivers should take special care when wrapping their bundle of joy. Swaddling should allow ample room for the baby’s legs to move, with plenty of space to bend the hips and knees. Swaddling may be best learned from watching a video that demonstrates the proper technique.

This video presented by the International Hip Dysplasia Institute shows techniques for safe swaddling:

In general the steps include:

  1. If using a square cloth, fold down one corner
  2. Place the baby on the cloth so that the folded corner is at shoulder level.
  3. Bring the left arm down or onto the chest. Wrap the cloth over the arm and chest and tuck the corner under the baby’s right side.
  4. Bring the right arm down or onto the chest. Wrap the cloth over the arm and chest and tuck the corner under the baby’s left side.
  5. Twist or fold the bottom end of the cloth and tuck behind or in front of the baby, ensuring that both legs can flex at the hips and knees and have ample room to move apart.

Another option is to use a sleep sack that leaves lots of room for the baby’s legs. Some commercially available sleepers may still be too tight on the legs. The International Hip Dysplasia Institute has a list of Hip-Healthy” products which can be found here.

StrollerTraffic: What signs should parents look for to gauge if baby is improperly swaddled?

Dr. Emily Dodwell: To ensure that baby has enough room for breathing, parents should be able to fit two or three of their fingers between the infant’s chest and the blanket or sleep sack. The blanket or sleep sack should be loose enough on the legs that the baby’s hips and knees can flex fully, and should have lots of room to move apart.

StrollerTraffic: What kind of fabric should parents use to swaddle their baby?

Dr. Emily Dodwell: Cotton is a good option throughout the year, as the fabric is light and breathable (I personally like muslin cotton). The shape of the material is typically square, although rectangular or triangular can also work. A good size for fashioning a swaddle is typically 3-4 feet across, depending on the size of the infant.

StrollerTraffic: Any other do’s and don’ts of proper swaddling?

Dr. Emily Dodwell: Babies should be placed on their backs to sleep to reduce the risk of sudden infant death syndrome (SIDS). It’s especially important to avoid positioning a swaddled baby on the stomach or side. The American Academy of Pediatrics advises that parents should not swaddle a baby past two months of age when babies may start to roll over. Swaddling should be stopped even sooner if the baby is showing signs of starting to roll.

In addition, it’s important for caregivers to make sure that the blanket used to swaddle does not become unwrapped, as loose blankets are not recommended around babies as there could be a risk of suffocation.

Swaddling can also increase the chance your baby will overheat, so its important to monitor temperature and comfort when a baby is swaddled.

StrollerTraffic: Thank you, Dr. Dodwell! We’re sure new moms — and even seasoned moms — will appreciate these tips!

Emily Dodwell, MD MPH is a Pediatric Orthopedic Surgeon at Hospital for Special Surgery.