Why do we wrap or swaddle?

I think most parents know exactly why we swaddle our babies.

Perhaps when our ancestors relied on a burning fire for warmth, wrapping a baby was mostly to keep them warm. But today, we swaddle our little babies to avoid that sudden flailing of the arms and head that suddenly snaps them awake, undoing all the it has taken to get to them to sleep. Also we swaddle to create that ‘being hugged’ feeling that babies love so much.

What is the startle reflex?

Babies are born with the Moro, or what is more commonly called the ‘startle reflex’. It begins in the first trimester in utero, and by birth it is fully developed. A loud noise, a sudden bright light, movement or even a parent laughing can trigger the reflex.

For anyone who hasn’t seen it, a baby’s whole body stiffens, their arms rapidly rise up and their back fully extends. Then, just as quickly, it seems to all subside and the baby bends into a fetal position with spine bent, legs drawn up and hands clenching close to the body. This innate response is prompting the little baby to curl up into a protective position after an initial alarm.

As a baby becomes better at moderating external stimuli, the intensity of their response lessens. From about 3 months old, the startle reflex begins to transform into more purposeful movements until it’s no longer present at about 6 months.

How do I help them sleep?

So we now know that the startle reflex is an innate protection mechanism, and seemingly harmless right? Sure. Except at sleep time!

Without a mature ability to filter sudden stimuli, even something like their own hiccups, means babies need some help to stay calm at sleep time. This is when tucking their arms close into their body can help them feel secure in their bassinet or cot, and help them stay asleep.

Our babies are just not designed for separation during sleep. They would love to spend the whole time bundled up in warm snuggly arms. But as effective as this would be, there are times (many times!) when we need to do other things in life, so this is when being swaddles comes into it’s own, to help create that sensation of being hugged.

Studies have shown that babies who are wrapped or swaddled spend less time crying than those without that containment. Plus they wake up fewer times in those early months and even show a reduced response to pain, when swaddled, so it may help them with an upset tummy.

How to swaddle and wrap safely

Easy breathing (not too tight)
Wraps and swaddles should allow for full and uninhibited chest expansion. Those little ribs are still very soft and bendy, and an overly enthusiastic wrap has the potential to be too firm across the chest.

Healthy hip development
Equally, the hips need to be able to flop outwards while the baby sleeps. There is evidence that late onset developmental dysplasia of the hip (DDH) is increasing in Australia. DDH is when the hip is either dislocated or prone to dislocation. Tight swaddles and wraps across the hips that hold the legs together are thought to contribute to this increase in DDH.

Babies don’t regulate their body heat very well, and rely on their coverings to keep them warm but not hot. This is a fine balance, so if you wrap or swaddle be sure to not overdress your baby underneath. Just imagine if you slept in a sleeping bag, with layers of clothes underneath and bedding on top.

Never cover a baby’s head at sleep time, e.g. with a hat or beanie, because this has been associated with overheating. And if you wrap, avoid using bunny rugs or blankets as they are bulky and have the potential to overheat the baby. 

Wrapping or swaddling needs to be secure, without any chance of draping over the baby’s face. It is sometimes difficult to wrap a baby firm enough to keep them contained while also not restricting their chest or hips.

This is where wearable swaddles or sleeping bags are great. There are no risks involved as long as:

  • they’re not constrictive across the chest
  • the neck is fitted and the baby’s head cannot slip down into the swaddle.

When babies have their arms in a swaddle or wrap, they can’t shuffle around to remove bedding that may fall over their face. So if you use a sheet or covering as well, be sure it is securely tucked in, not too hot and certainly not heavy on the baby’s chest.

Sharing a sleep surface
If you sleep with your baby or plan to, it’s recommended that you don’t wrap babies, and ensure there are arms free and reduce the risk of overheating.

When do I stop wrapping or swaddling?

When your baby begins to roll onto their tummy, they NEED their arms free. This is the time to stopping wrapping and swaddling them. If your swaddle or sleeping bag has armholes, you can let your baby sleep with their arms out of the swaddle. To ease them into it, a great idea is to try just letting one arm free to start.

If you’re wrapping instead of using a sleeping bag, make sure the remainder of the material is secure and not at any risk of lying over your baby’s face if you are wrapping your baby with one arm out.

Helen Stevens. Registered Nurse, Midwife and Maternal Child and Family Health Nurse, with qualifications in Infant Mental Health and a range of early childhood interventions. As author, researcher, educator and clinician, she has specialised in infant sleep for over 20 years and has world recognition for her work.

Go to www.helenstevens.com.au for more great information and help for parents.

Helen Stevens