AAP guidance describes this as a reflex. Tell your clinician if movements seem different on one side.
Glossary
Moro reflex (startle reflex)
A newborn startle response involving an outward movement of the arms followed by bringing them back in.
In a sentence
What does “Moro reflex (startle reflex)” mean?
A newborn startle response involving an outward movement of the arms followed by bringing them back in.
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Related terms
Sources
General information, not medical advice. For concerns about your child, talk with your doctor or child-health nurse.