February 05, 2020 3 min read

Newborn Sleep Sacks and Newborn Cocoon Wrap

Cocoon Baby Swaddle Bags are designed to be both easy to use and difficult to escape from. The simple stretched cocoon or a zip up design will keep baby snug and securely swaddled without the need for complicated wrapping.  Why do we wrap or swaddle a baby? 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, these cozy and comfortable swaddle cocoons at Zero to Three Club are perfect for the job.


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. 


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. 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. At Zero To Three Club we have a curated collection of muslin cotton swaddles and Muslin Bamboo Swaddles that are deem to be the best in class for the job.


How to swaddle and wrap safely.

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.

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 different parts of the globe. 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. Consider these lightweight durable bamboo swaddles  and  cotton swaddle sack from Zero To Three Club.


If you are struggling with the wrapping technique, wearable swaddles or sleeping bagsare great. There are no risks involved as long as they’re not constrictive across the chest and 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.


When do I stop 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. More of this topic for another post.


Written by 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 specialized in infant sleep for over 20 years and has world recognition for her work.