All parents of newborns have seen it. One minute your baby is sleeping blissfully and you're convinced she'll be down for hours. Then all of a sudden, her arms jerk, she wakes herself up, and you're back at square one trying to get her down to sleep again. This is what's called the Moro (startle) Reflex. It's a protective automatic reflex that all babies are born with. So it's completely normal!
Here we'll outline:When does the Moro (Startle) Reflex disappear?
So what is the Moro reflex exactly? The Moro Reflex, or you might hear someone refer to it as the startle reflex, is an involuntary response experienced by newborn babies. It's a normal occurrence parents will notice their babies doing from birth until 4 months or so. This reflex is often a response to an outside factor, but can also be triggered when a baby feels a free-falling type sensation. You'll know your baby is experiencing the Moro reflex if you see them suddenly flail out their arms or arch their back. They may also let out a gasp, cry out, or breathe in a sharp inhale.
It sometimes comes completely out of the blue with, what seems to you, no particular reason for it. Then as quick as it came, they'll sometimes just as quickly pull their arms back in again and calmly go back to sleep. Unfortunately, more often than not they're awake for good.
The Reasons Babies Experience the Moro Reflex
There are various reflexes that are all a natural part of infancy - ones that your child's healthcare provider will screen for. The Moro (Startle) reflex is one of them. Just like animals have adaptations to protect themselves, babies, too, have this type of adaptation as a form of protection. In fact, it shows up as soon as 28 weeks gestation!
The Moro Reflex isn't usually random even if it may appear that way to you. When your baby goes through this, something has caused them to feel as if they are falling. The reason they throw out their arms is as if to try to "catch" themselves - just as you would if you were falling.
These are factors that may trigger your newborn's Moro Reflex:
- bright lights
- outside noises
- a sudden or cold touch
- a quick movement by someone around them
- being placed down in a crib
- change of direction
The changes in the environment may be barely noticeable to you. But they can be strong and overwhelming for your baby's senses, who isn't yet adjusted to the outside world.
Parents may notice the Moro reflex happening often when they place their baby down on their back to go to sleep. You'll think they're completely asleep (and they probably are) and as soon as you lay them on their back, they startle themselves awake and start crying. This can be a scary feeling for a baby, so it's not surprising that it completely wakes them up. They are responding to an uncomfortable stimulus and looking out for protection. Of course, YOU know that they are just fine, but their tiny little nervous system is reacting just as it should.
The video above, by Nina Gold, MD for OPENPediatrics, demonstrates how your child's pediatrician will perform the Moro reflex test. (If there is the absence of the Moro Reflex it will likely be noticed at one of your infant's well check-up visits. But if you have concerns, you should consult your pediatrician.)
Why does the Moro Reflex in newborns happen?
Even though you are gently laying your new baby down, the descent may give them the sensation that they are free-falling with nothing to catch them. Sounds scary, right? Their body responds in a protective manner which we see as being startled. It's really your little one's first attempt at protecting themselves against danger - just as you would do if you were in harm's way. It is believed that this survival instinct is the baby's way of reaching out to cling to its mother. Pretty amazing.
Webster's Dictionary gives the following medical definition of "Moro Reflex":
Luckily, there are a few main ways that you can help ease the Moro reflex for your little one.
Ways to Help Your Baby Avoid Startling From the Moro Reflex
Nothing that you do can completely eliminate the Moro reflex. It is an innate response that your baby will eventually grow out of. Until they do, here are the best ways to help your baby to not get startled so easily and hopefully help them (and all of you) sleep better:
- Reduce outside triggers. Try to keep lights dim or at an even intensity. If there is outside noise that can't be avoided (such as traffic) consider using a white noise machine or calming music (as we discuss here) to drown it out. If you have to move around your baby while they sleep, do it as calmly as possible. Be on the look out for specific triggers for your little one, in particular. There may be something recurring that you can easily eliminate.
- Hold your baby close to your body as you lower them down into their crib. The more that your baby feels protected, the less likely they will startle. Lay them down as gently as possible. Once you've laid your baby down in their crib, keep your hands placed on their body for a few moments. Take your hands away one at a time and slowly. This will allow them to settle in and avoid feeling the free-falling sensation.
- Swaddle your baby. This is one of the top reasons why newborn babies should be swaddled. Not only is it recommended by the American Academy of Pediatrics as an effective technique for calm and safe sleep, but it also helps infants to fall asleep faster and stay asleep longer. One reason is its ability to counteract the Moro reflex. By keeping your baby's arms tucked in tight against their body, they won't be able to jerk their arms out which ultimately scares them and wakes them up. Not only that, but the womb-like environment that's created from the swaddle will help keep them from feeling the falling sensation that often triggers the Moro reflex in the first place.
You might be thinking the first two sound pretty simple to do, whereas perfecting that swaddle technique is an art form you just can't seem to master.
That's where the Dreamland Baby Weighted Swaddle comes in.
It offers a fool-proof swaddle that wraps tightly around your baby's arms and chest. It also has an additional feature that will help fend off any startling your baby might experience. This swaddle is special because it's weighted. Remember we mentioned how comforting hands on your baby and keeping them close to you can keep them from startling? The weight provided by the sleep sack mimics the feeling of a hug - which is the type of protection they are seeking. It also increases serotonin and melatonin levels that help your baby relax. Though swaddling, in general, helps a lot with the Moro reflex, the weight provided is an added feature proven to relax your little one.
Here's what one mom is saying about the Dreamland Baby Weighted Swaddle she used during the Moro Reflex age:
Helping Calm Your Baby When They Experience the Moro Reflex
Even with the most thoughtful care given to your newborn baby while they are falling asleep or in the midst of dreamland, it's inevitable that the Moro reflex will occur at one time or another. So, what can you do to help your baby fall back asleep or calm them when this happens?
Even though we do recommend ultimately teaching your baby to fall back asleep independently, at this young of an age, and with the feeling that comes with the Moro reflex, it's best to comfort your baby. This way they realize right away that they are safe and will calm more easily. This includes:
- gently tucking your baby's arms and legs back in
- swaddling or re-swaddling - even if a swaddle was already on, sometimes a swaddle will have loosened and this can give them back the close comfort they lost momentarily
- holding your baby tucked in close to your body
Ultimately your baby wants to feel safe, protected, and loved. Instinctually you'll probably do this anyway, but this will get them back to sleep much more quickly than allowing them to try on their own.
When does the Moro (Startle) Reflex disappear?
The Moro reflex is just one of the many reasons your baby might not be able to sleep well. The suggestions provided, especially the weighted swaddle sleep sack, will help a lot. The other good thing is that this natural response won't be around forever. You're probably wondering how long the Moro reflex will last!
Over time, you'll see the jerky movements become less and less pronounced. Somewhere between 4-6 months of age (remember that all babies are different!) you will no longer see your baby experiencing this reflex. Interestingly enough, this is around the same time your baby will start to roll over. Strengthening of the muscles go hand-in-hand with the Moro reflex subsiding. Swaddling (which is only safe for babies who can't roll yet) will make way for sleep sacks, instead.
Although your baby's Moro reflex will eventually go away, you'll want to continue the calming habits you've put into place such as white noise, careful placement in their crib, and using a weighted wearable blanket in place of a swaddle (once they learn to roll). They'll be used to these routines by now, and continuing them will help to ensure that your baby continues to sleep comfortably and soundly.