Moro Reflex

What Is the Moro Reflex?

The Moro reflex, often referred to as the “startle reflex,” is one of the many primal/primitive reflexes present in infants from before birth. It is a physical reaction to sudden stimuli in a baby’s environment—most frequently a response to sound or movement. For example, when an infant is laid down suddenly or hears a loud noise, you might observe their arms and legs quickly extending outward before retracting in, almost as if they’re trying to cling to their caregiver.

This response isn’t just about movement; there’s often an emotional component as well. The startled baby may let out a cry after being surprised. This sudden outburst—both physical and vocal—isn’t random. The Moro reflex serves the vital purpose of alerting a caregiver to potential danger or distress. When an infant is startled, the response is powerful enough to prompt quick action from those nearby, helping to keep the baby safe and secure.

The Moro reflex triggers a release of stress hormones such as cortisol throughout the baby’s body, pushing them into a classic “fight, flight, or freeze” state. These chemicals heighten alertness and readiness for action in response to danger, even though the “danger” might be as innocuous as a gentle shift in the child’s position. Once the caregiver reassures and comforts the infant, those stress hormones dissipate, and the baby returns to a calm state.

Typical Timeline of Development of the Moro Reflex

The Moro reflex follows a fairly predictable developmental path in human growth. This reflex develops in utero and remains active for about the first six months of life. In a typically developing baby, it is integrated at that time into a more sophisticated startle response that does not involve the dramatic limb extension seen in newborns. As integration occurs, the baby’s nervous system gradually replaces this automatic, whole-body reaction with more controlled, higher-level nervous system responses.

What Symptoms Appear If the Moro Reflex Is Retained?

If, however, the Moro reflex persists beyond this integration window, it may signal that the reflex has not fully resolved—what clinicians call a “retained” reflex. Monitoring the timeline and development of this reflex, therefore, is an important part of early pediatric assessment for occupational therapists, pediatricians, and parents alike.

Most infants move on from the Moro reflex as designed. But sometimes, this reflex becomes retained, continuing to affect children well past the typical integration period. Instead of looking like a baby’s startle, a retained Moro reflex manifests in different ways in older children and adults. The following symptoms suggest a retained Moro reflex:

Anxiety and Heightened Stress Response

If an older child experiences chronic anxiety across a variety of routines and environments, this may be a sign that the Moro reflex is still present. Children with a retained Moro reflex can feel on edge, hypersensitive to stimuli, and constantly ready for “fight or flight,” a state not appropriate for day-to-day life outside the context of real danger.

With the Moro reflex closely tied to the body’s stress response, some children who retain it may experience challenges such as blood-sugar dysregulation, sensitivities (including food or environmental), or other signs of a system working harder to stay regulated. These experiences are influenced by many factors, and the retained reflex is one aspect to consider within a larger health and developmental context.

Emotional Regulation Difficulties

A second marker is difficulty with emotional regulation. Children may seem emotionally “hot and cold,” swinging quickly between moods and struggling to maintain a calm emotional state. The reflex’s original purpose—to jolt the baby into alertness in response to sudden change—means that if it persists, the child may be perpetually on alert, unable to settle or self-soothe easily. This emotional turbulence can affect relationships, learning, and general well-being.

Motion Sickness

A pronounced tendency towards motion sickness is common in chidlren and adults with a retained Moro reflex. Those who have it often get carsick very quickly or find themselves nauseous during even mild movement activities, like riding a Ferris wheel, swinging on a swing, or riding a merry-go-round. The underlying reason is a disconnect in how the body perceives and adjusts to changes in motion—originally triggered during the dramatic limb-extension of the Moro response—due to a dysregulated vestibular system.

Balance and Coordination Issues

Apraxia and dyspraxia are balance and coordination challenges that often accompany a retained Moro reflex. Since the Moro reflex originally impacts the whole-body reaction to movement, its persistence can prevent the development of smooth, coordinated control required for activities that demand balance and postural stability. Postural control is often difficult, resulting in children who appear “disconnected” in their body’s movement patterns.

Other Potential Signs

Other associated issues of a retained Moro reflex include:

• Hypersensitivity to lights and sounds
• Chronic distractibility
• Trouble with attention and focus
• Difficulty in social settings

It is very common for a child with a neurodevelopmental disorder such as autism, ADHD, learning disabilities, developmental delays and Sensory Processing Disorder to have a retained Moro reflex and quite likely many other retained reflexes.

What Causes a Retained Moro Reflex?

We encourage you to read the section entitled Regression of Milestones in our Developmental Delays Main Info Page as well as the section entitled What Can Pause, Impair, or Interrupt Brain Development? in our How a Child’s Brain Develops article for detailed information. The retention of the Moro reflex can be due to birth trauma, environmental toxins, head injury, chronic ear infections, significant illness, or other early developmental disruptions. It’s often a combination of influences rather than a single cause.

What Can Be Done for a Retained Moro Reflex?

Addressing a retained Moro reflex is both possible and beneficial, especially when individualized, functional activities are used. An occupational therapist who is knowledgeable about reflex integration will typically encourage practical approaches that engage the child in active movement and sensory experiences. Please note that not all occupational therapists have this kind of training.

Functional Exercises for Integration

Here are a couple of examples of exercises that a therapist might use to help your child integrate their retained Moro reflex. Keep in mind these exercises should be done in a safe and supported environment, as moving too quickly or without care, may exaggerate, rather than integrate, the startle response. One example is a “head-tilting” exercise while lying on a bed. Starting with the child’s head hanging off the edge of the bed, he or she will be encouraged to lift, then lower the head to a slow count of eight (approximately 8 beats of a metronome set at 60 beats per minute). The child then alternates positions, completing the pattern on the left side, right side, back and tummy.

Another example involves the use of a yoga, or therapy, ball. The child may be positioned on their stomach or back over the ball (gently supported by their caregiver or therapist as needed). He or she is then encouraged to reach for and grab a toy—such as a bean bag or stuffed animal. After retrieving the object, they are then given the opportunity to return comfortably to a safe, seated position and toss the toy toward a target. The critical element in these exercises is the change in head position as the child lies over the ball or bed. The purposeful movement stimulates the vestibular system and directly engages the neurological circuits associated with the Moro reflex. It helps the nervous system learn to process motion in a new, mature way, encouraging the integration of the reflex and helping to reverse signs and symptoms associated with reflex retention.

Tips for Implementing Integration Activities

Feelings of safety and support are critical. If the child is apprehensive about going backward over the ball or bed, or if they become noticeably fearful if their feet leave the ground, provide extra stability. Caregivers should always stabilize the child’s legs and offer support, making the exercise both a nurturing and therapeutic experience. Hesitancy or discomfort with the movement can be telling; it may indicate that the Moro reflex is significantly retained and impacting the child’s day-to-day function.

It’s important to remember that these activities are not diagnostic tools but an integrative exercise. Formal assessment for retained reflexes should always be conducted in person with an experienced professional, such as an occupational therapist who has knowledge of and training for dealing with reflex integration. We may have someone in your area listed in our practitioner directory, and you can also find help from telehealth therapy providers such as Brain Harmony and MovePlayThrive.

Other Tips for Those with a Retained Moro Reflex

There are many ways to help calm the fight–flight-or-freeze response common to those with a retained Moro reflex. In addition to finding a therapist that can help integrate the reflex, as mentioned above, anything you can do to create a sense of calm for your child will help. Always remember that the body cannot heal unless it is in a state of calm, so find those things that can help get your child into this state, whether it’s a practice of gratitude, getting into nature, doing breathwork, having acupuncture done, having chiropractic or craniosacral therapy work done, doing heavy work or many of the other mind-body-spirit therapies. There are many choices out there, and many of them are free. We also encourage you to do these things for yourself because you being in a state of calm will also help your child to heal.

The Importance of Individualized Support

Because every child is different, there is no universal intervention. Some children may benefit from daily movement games, structured therapy sessions, or even classroom sensory breaks based on their unique needs and developmental stage. The goal is always to make integration exercises functional and fun—ensuring that the learning and neurological adaptation occur in a motivating, positive context.

Conclusion

The Moro reflex is a critical milestone in early childhood development, providing necessary protection and alertness during the newborn stage. Typically, it fades by six months as more sophisticated neurological responses take over. When it persists—becoming a retained reflex—it can lead to anxiety, emotional dysregulation, motion sickness, and coordination problems. Through thoughtful, functional activities and close observation, parents and professionals can both ease the reflex’s effects and help children reach their full potential. Advances in occupational therapy and parent education are making it easier than ever to recognize, assess, and integrate the Moro reflex, ensuring every child gets the best possible start.

About Maria Rickert Hong CHHC

Prior to working on Wall Street, she was a marketing specialist for Halliburton in New Orleans, where she also received her MBA in Finance & Strategy from Tulane University.

She is the author of the bestselling book Almost Autism: Recovering Children from Sensory Processing Disorder and the co-author of Brain Under Attack: A Resource for Parents and Caregivers of Children with PANS, PANDAS, and Autoimmune Encephalitis. She is a co-author of Reversal of Autism Symptoms among Dizygotic Twins through a Personalized Lifestyle and Environmental Modification Approach: A Case Report and Review of the Literature, J. Pers. Med. 2024, 14(6), 641.

Maria is also a Certified Holistic Health Counselor. Her work can be found on DocumentingHope.com, Healing.DocumentingHope.com, Conference.DocumentingHope.com and MariaRickertHong.com

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