The Moro Reflex and Swaddling

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There's a moment almost every new parent experiences. Baby is finally, beautifully asleep. You hold your breath, lower them gently into their bassinet, and just as you dare to exhale, their arms fling wide, their face crumples, and the crying begins again. Say hi to the Moro reflex - they'll be here a little while so grab your drink of choice and let's settle in for a chat.
Love To Dream
7 min read |
11 May, 2026

The startle reflex is one of the first little challenges of new parenthood and like most of them, it's temporary. With the right knowledge and the right swaddle, those early weeks of broken sleep become a little more manageable for everyone.

What is the Moro reflex?

The Moro reflex, also sometimes referred to as the "startle reflex" is one of the most primitive reflexes a baby is born with. When triggered, your baby will suddenly fling their arms outward, extend their legs, and quickly pull back in, sometimes crying in the process.

It's completely involuntary, and it's a sign of a healthy nervous system. According to the NIH, the Moro reflex is present from as early as 25 weeks gestation and its absence at birth is considered clinically significant so seeing it is a good sign. If you're ever unsure, it is always worth talking to your chosen medical professional for personalized advice.

Why does it keep waking my baby up?

The Moro reflex doesn't distinguish between a real threat and a peaceful bassinet. It can happen at anytime or that slight sensation of being lowered into a crib can be enough to trigger it - which is why so many babies fall asleep in your arms and wake the moment they're put down.

It can be frustrating (especially if you have been waiting patiently for a shower or a snack) but it's helpful to note as it's a reflex, working with it, not against it - is the best way to protect your sleep and their development at the same time.

What does the Startle Reflex look like?

When does it go away?

The Moro reflex typically begins to fade around 12 weeks and disappears completely by 6 months as your baby's nervous system matures. This is also when the 4-month sleep regression hits — so having a swaddle transition plan ready before then means you're not caught off-guard when both happen at once.

How Swaddling Helps Manage the Startle Reflex

Swaddling is one of the most effective ways to help your baby sleep through the startle reflex. By gently wrapping your baby, you:

  • Calm the reflex: When your baby's arms are gently secured, the startle reflex is less likely to wake them up
  • Create a womb-like environment: Swaddling mimics the snug feeling of the womb, which is naturally calming for newborns
  • Reduce sleep disruptions: With fewer sudden awakenings, your baby can enjoy less disrupted, more restorative sleep periods*
  • Promote better sleep quality: Deeper, uninterrupted sleep supports healthy development and gives parents much-needed rest
  • Provide comfort and security: The gentle pressure of swaddling has a soothing effect that helps babies feel safe and secure

*Always follow professional feeding guidelines for your baby. Most newborns require feeds every 2-4 hours.

Learn more

Swaddling
Transitioning

Is swaddling safe?

Yes, when done correctly. Both the AAP and First Candle recommend the following:

  • Always place baby on their back. A swaddled baby should only sleep on their back — never on their tummy or side.
  • Give the hips room. Swaddling should be snug around the chest but allow ample room at the hips and knees to avoid contributing to hip dysplasia.
  • Watch for overheating. Signs include sweating and flushed cheeks. Dress baby in breathable layers and follow a dressing guide appropriate for the room temperature.
  • Stop at the right time. When your baby shows any signs of attempting to roll (anywhere between 8 weeks to 3 to 4 months) it's time to stop swaddling and transition to a sleeveless option for safety.

Types of Swaddling: Finding the Right Fit for Your Baby

At its heart, swaddling is all about recreating that cosy, secure feeling your baby had in the womb. For nine months, they were snugly held in a warm, contained space, so it makes sense that they find comfort in something similar on the outside.

That's what swaddling does. It gives your baby gentle, all-around comfort that says "you're safe, you're secure, it's okay to sleep."

But not all swaddling looks the same, and what works beautifully for one baby might not suit another.

There are two key things to consider when it comes to swaddling:

  1. The position (where baby's arms go)
  2. The style (how the swaddle actually fastens).
Arms-Down vs. Arms-Up

Arms-down swaddling is the more traditional approach. Baby's arms are placed by their sides or across their chest and held gently in place. Some babies settle well this way, but others can find it frustrating. Ever noticed your baby on an ultrasound with their hands up by their face? Working against that can cause some babies to feel unsettled so if you've tried traditional swaddling and it's only led to frustration, the arms positioning could be why.

Arms-up swaddling is a more modern approach that swaddles with hands by the babies face so they can access their hands for a familiar, instinctive self soothing.

Which is better? A wrap, velcro or zip-up swaddle?

Wrap swaddles

These are the traditional option, usually a large muslin or cotton blanket that you fold and tuck around baby in a specific way. They're versatile and you can adjust the tightness, but they do take a bit of practice to get right. They can also be inconsistent if you and a partner are both wrapping the baby over the course of the day/night. Some particularly wriggly babies may also have a talent for escaping them mid-nap so extra care is required to ensure their sleep space remains safe with no loose layers.

Velcro swaddles

These use velcro tabs to fasten the fabric in place, which makes them quicker and easier than a wrap. They're a good middle ground between adjustability and convenience, though the velcro can sometimes come undone with a determined wriggler, and that ripping sound isn't ideal when you're trying to do a stealth re-swaddle at 3am.

Zip-up swaddles

These are the simplest to use. Baby goes in, you zip up, done. No folding, no tabs, no technique required. They're consistent every time (which is great when someone else is doing bedtime or you're 3 hours of broken sleep into an evening) and there's no loose fabric to worry about. The trade-off with some zip-up styles is less adjustability, but a well-designed zip-up swaddle will have the fit according to the weight of the baby, not age so should be fit for purpose.

What Should I Look for in a Swaddle?

When looking for a swaddle for your newborn, consider ease of use, safety and quality. Here's what that actually looks like in practice:

  • Calms the Moro reflex without suppressing it so the reflex can still develop naturally, but won't jolt your baby out of a deep sleep
  • Allows an arms-up sleep position giving baby access to their hands to self-soothe, just like they did in the womb
  • Recreates womb-like security the snug, familiar feeling that newborns find instinctively calming
  • Keeps baby safely on their back in line with AAP safer sleep guidelines
  • Has genuine stretch and give so baby has freedom of movement within the swaddle, not just containment
  • Supports a still-developing nervous system giving it a gentle, consistent boundary in a world that suddenly feels very wide open

So Which Swaddle Is Right for me?

Every baby is different, and a bit of trial and observation is expected with a newborn. Watch how your baby naturally positions their arms when they sleep. Notice whether they seem to fight against being contained or relax into it. The best swaddle is the one your baby is comfortable in, that you feel confident using (especially at 2am with one eye open), and that keeps them safe.

In Love & Dreams,

LTD

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