Moro Reflex

What is Moro reflex?

You might have noticed your baby making jerky movements during a sleep or producing an alarming response whenever he hears a loud noise. It’s nothing but the Moro reflex that babies are born with. As soon as he hears something unusual or if he is feeling insecure, your baby may tighten his body, fling the arms up and out and open his tightly clenched fists. Then he draws up his knees and brings back his arms and re-clenches the fists. Moro reflex is nothing but a first step to protect him from harm and is considered to be a protective motor response against disruption of body balance or extremely sudden stimulation.

Triggers of Moro reflex

The common triggers of Moro reflex are

·         A loud noise.

·         A sudden touch.

·         An unexpected change in the intensity of light.

·         Sensation of falling (Example: Placing a baby in a crib, picking your baby from a bath tub).

·         Any change in the direction of the baby's body.

 

When does this reflex start?

This reflex is seen right from the birth. More accurately this reflex develops during 28 to 32 weeks of gestation. As your child adapts to the environment and the sounds, this reflex may start to diminish around 3 months and becomes completely absent around six months.

How to identify this reflex?

Ernst Moro was the Austrian pediatrician to identify the reflex in 1918. He stimulated the reflex by slapping the pillow on both sides of the child's head. Now the common method to test the reflex is the “head drop” method. In this method, the child will be placed face up on a soft, padded surface and slanted suddenly so that his head is a few centimeters lower than the level of the body. As he suddenly experiences an unusual change, you can notice your child producing a Moro reflex.   

Clinical Significance

Moro reflex is usually weak in preterm infants due to low muscle tone. The absence of the Moro reflex can result from injuries from birthing process, intracranial hemorrhage, infection, brain malformation, general muscular weakness, peripheral nerve damage and spastic cerebral palsy.  

Absence of Moro reflex means that the child has some form of abnormalities. When this reflex is absent on both sides, it means a child has damage to the brain or spinal cord. When this reflex is absent on one side, it means there is either a broken shoulder bone or an injury to nerves. The common causes of asymmetric Moro are damage to a peripheral nerve, cervical cord, or a fracture of the clavicle. This can result in inhibition of the reflex on the affected side.

Your paediatrician will identify the reflex right from the birth of your child and during your regular visits. If any abnormality is seen, a complete physical examination will be done and detailed family history will be collected. The child’s muscles and nerves will be examined and diagnostic tests like shoulder x-ray and tests associated with brachial plexus injury will be done to identify the cause of abnormality. The prolonged retention of the reflex can be a sign of spastic cerebral palsy.

 

If you could not identify this reflex in your child, early interventions can help to overcome the issue. Physical therapy, occupational therapy and a developmental specialist can help rectify the problem.