Startle Reflex in Newborns - What Is It and How to Control It?

Startle Reflex in Babies- What It is and How to Control It

Early in parenthood, you might find yourself wishing that the baby came with a manual so that you can understand him better. You might be worried about every movement your child makes, and wonder what his movements mean. Some of his movements and reflexes are simply hard to comprehend.

Of the many reflexes that you will observe in your child, most are harmless. Rooting and sucking reflexes help the child breastfeed, and are not a problem for the parents to worry about. However, some reflexes can be a little troubling, namely the Moro Reflex or Startle Reflex.

What is Startle Reflex in Infants?

Babies usually exhibit around nine reflexes right from the time they are born, and the Moro reflex is one among those. Also called the startle reflex, this is said to occur when the baby suddenly wakes up from his sleep. The action might seem unnatural and even harmful, as it is not anywhere close to the way the child wakes up normally, he might pull his knees, and raise his arms, only to go back to the fetal position again.

Is Startle Reflex an Issue in Newborn Babies?

The Moro reflex does not indicate any sort of disorder in the baby whatsoever, it is in fact, an indication of a healthy nervous system. If the baby startles out of his sleep, it means that the nervous system of the child is working perfectly. However, it does not mean that the child will enjoy waking up abruptly, he might end up crying and may even refuse to go back to sleep again.

What Does Baby Moro Reflex Look Like?

There are two phases of the baby startle reflex during sleep. In phase one, the arms of the child flail and the baby seems to inhale abruptly. This is followed by loud cries and fussy behaviour. This occurs because the baby feels the sensation of free fall, and reacts to it by stretching his arms out. The second phase is all about the baby going back to the fetal position, in a similarly abrupt fashion. This is because the baby is wired to protect himself from the ‘fall’, and the fetal position gives him the best chance to do that.

A mother holding her baby in arms

What Triggers Baby Startle Reflexes?

The startle reflex is triggered due to some external stimuli, and some of them are given below. Know why they occur:

  • Auditory: If there occur any sudden noises like a slamming door or a clang of a pot, the reflex may kick in.

  • Visual: Changes in the amount of light in the room can also cause the reflex to kick in.

  • TouchIf you are holding your baby, any sudden movements like standing up can also cause a reaction in the child.

  • Shifting: If you make the child feel unsupported by your action, like if you are in the process of laying your child down on the bed, it may trigger the Moro reflex in him.

When Does Startle Reflex Start?

The startle reflex is present in children from birth itself. Your child will exhibit the reflex right from the time he is born, and it is completely normal too.

How Long Does Moro Reflex Last in Babies?

Present from birth, this reflex gradually disappears by the time the baby turns six-months-old. As the muscles of the baby develop, he is able to balance better and it is during this time you should support himself well during sleep.

Age-wise Stages of Startle Reflex

The stages of the Moro reflex change according to the age of the child, as given below.

0 to 1 Month

At this stage, the world is something strange to the child. Startle reflex occurs often, and swaddling might help the baby sleep better.

2 to 3 Months

The baby is more accustomed to your touch, so he will be calm by this age and will sleep better in your embrace. Even if he wakes up during his sleep in an abrupt fashion, your gentle touch may help him go back to sleep quickly.

4 to 6 Months

The muscles of the neck and back develop by this time, so the baby is able to balance himself during his sleep. This means that he is more likely to sleep through and Moro reflex gradually dies out.

How to Reduce Moro Reflex in Infants

Here are a few ways to help your child through startle reflexes:

1. Swaddling

The baby feels safe and secure in the warm embrace of a blanket, so the startle reflex incidents may reduce if you swaddle the child comfortably.

A mother swaddling her baby

2. Babywearing

This option is even better than swaddling, as the baby always remains in contact with his mom or dad throughout his sleep. This reduces startle reflexes to a great extent.

3. Co-sleeping

Co-sleeping not only calms the baby down in his sleep but also makes it easier for a parent to attend to the child in the middle of the night without losing much sleep.

4. Transferring methods

In most cases, the Moro reflexes kick in because of abrupt movements that occur as the baby sleeps. Therefore, you can handle the baby extremely gently once he goes to sleep so that his sleep is not disturbed.

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When to Consult a Doctor

If you observe that the reflex seems to affect one side of his body more than the other, it can be an indication of problems with the nervous system, paying your doctor a visit is necessary, at this stage. Even if you have not yet noticed this reflex in the child, your doctor will be able to observe it when you visit him.


1. What If an Infant Does Not Have Startle Reflex?

The lack of Moro reflex in the child can be an indication of problems with the brain, spinal cord, or even both. Since the reflex is an indication of a great nervous system, you should consult the doctor if you feel that it is not present in your child.

2. What if a Baby Rarely Startles?

While most parents do notice this reflex in the early days, some babies might startle in a subtle manner that parents could miss. Therefore, you should never try to startle your baby intentionally when he is asleep. If you have any doubts on this reflex, consult a paediatrician.

Moro reflex is a natural condition in newborns and is something that is an indication of a proper-functioning nervous system. If you feel that it is not present in your child, you should consult the doctor immediately. However, remember not to stress, as it is rarely an issue.

Also Read: Newborn Baby Reflexes

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