The Moro Reflex, also known as the startle reflex, is an involuntary, automatic reflex observed in newborns and infants. It is typically triggered by a sudden change in position or a feeling of falling. The reaction involves the baby spreading out its arms and legs, then retracting them, often followed by crying.

Key Takeaways

  1. Moro Reflex, also known as the startle reflex, is an involuntary response that newborn babies have to sudden changes in their environment or a perceived threat. It typically involves spreading out the arms (abduction), unspreading the arms (adduction) and crying, usually occurring 2-3 seconds after the disturbance.
  2. It’s a key marker of appropriate development in newborns. Present from birth until about 6 months of age, the Moro reflex gradually disappears as the baby’s nervous system matures. If this reflex is absent or abnormal, it may indicate an issue with the baby’s nervous system.
  3. The Moro reflex is one of many reflexes that pediatricians look for during baby wellness checks. If the reflex persists past the 6-month mark, it can be a sign of neurological issues and might require further medical evaluation.


The Moro reflex, also known as the “startle reflex”, is a significant aspect of motherhood and child development. This reflex is an automatic response observed in newborn babies from birth to around 3 or 4 months of age, which helps in their survival.

It consists of distinct responses such as throwing back the head, extending the arms and legs, crying, and then drawing the arms and legs back in. This reflex is important as it serves as an indication of the baby’s neurological wellness and development.

It is a significant part of the baby’s adaptation to life outside the womb and their consequent growth. It is essential for mothers to understand the Moro reflex as it helps them to comprehend their baby’s reactions and needs better.


The Moro reflex, often observed in newborn babies, is an automatic response to a feeling of loss of support or a sudden sense of falling. It serves a crucial role in the early stages of a child’s development, particularly related to survival instincts.

When a baby feels as though they’re falling or if they’re startled by a loud sound or movement, the Moro reflex triggers a feeling of alarm, causing the baby to spread their arms (as if trying to grasp something) and then retract them, often followed by crying. This is the baby’s primitive fight or flight response.

The primary purpose of the Moro reflex is to protect the infant. As a reaction to any potential threat or changes in the environment, it helps draw the attention of caregivers, ensuring the baby’s needs are met and their safety is secured.

Additionally, it aids health professionals in assessing the proper functioning of a baby’s nervous system. If the Moro reflex isn’t present or if it continues past six months, it could indicate underlying issues with the baby’s neurological development and should be evaluated by a healthcare provider.

Examples of Moro Relfex

As a newborn: During regular check-ups with a pediatrician, one common evaluation is the testing of the Moro reflex. When the infant’s head shifts quickly or falls back slightly, the reflex is triggered, causing the baby’s arms to thrust outward and then curl back in as if embracing. If this response is not observed, it may indicate a neurological problem, such as brachial plexus injury or fractured clavicle, which requires further examination.

During nap time: Babies often exhibit the Moro reflex while peacefully dozing off in their crib. When the baby is laid down, a sudden feeling of falling may cause them to startle and exhibit the Moro reflex, spreading their arms wide and then tucking them back in. This is a perfectly normal part of newborn development and lessens over time.

While swaddling: When new parents swaddle their infants for the first time, they may notice the Moro reflex. The baby might suddenly throw out their arms and startle in response to the snug feeling of the swaddle. As swaddling can help to mimic the familiar, cozy environment of the womb, it can actually be used as a strategy to help calm a baby’s Moro reflex and soothe them to sleep.

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Moro Reflex FAQ

What is the Moro Reflex?

The Moro reflex, also known as the startle reflex, is one of many reflexes that babies are born with. It’s a normal part of infancy and disappears after a few months. When the Moro reflex is triggered, a baby will usually respond by stretching out their arms and legs and then pulling them back in.

What triggers the Moro Reflex in babies?

The Moro Reflex can be triggered when your baby is startled by a loud sound or movement, particularly if it involves a quick change in their body’s position. Things like a door slamming, a dog barking, or even being put down on their crib suddenly can set the reflex off.

When does the Moro Reflex start and stop?

The Moro Reflex develops while your baby is still in the womb, typically around 25 to 28 weeks of gestational age. This reflex usually disappears around 2 months of age, but it can last until they are 6 months old in some babies.

Is it bad if a baby doesn’t have a Moro Reflex?

If a baby doesn’t demonstrate a Moro reflex, it could signify a problem with their nervous system and should be brought to a doctor’s attention. However, it’s also important to note that not all babies will exhibit this reflex in a way that’s noticeable to parents or caregivers.


Related Motherhood Terms

  • Infantile Reflexes
  • Startle Reflex
  • Newborn Development
  • Motor Skills Development
  • Neonatal Behavior

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