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The Newborn Startle Reflex

With the actual dictionary definition of ‘The reflex response of an infant in which the limb and neck muscles contract when the infant is allowed to drop a short distance or is startled by a sudden noise or jolt’ one might wonder if the startle reflex is dangerous for their infant. The answer is no.

newborn-startle-reflex.jpgInfants are born with this primitive reflex, also called the moro reflex, that helps them adapt and adjust to situations. You will often see a newborn jump when laid on a bed, even softly, showing that their muscles and reflexes are working properly. More common is having your baby startle when you start the vacuum cleaner in the room they are in, however not wake up. This is a good sign that your babies hearing is working up to par.

There are several things that may set your babies startle reflex off. They include but are definitely not limited too:

  • Running the vacuum
  • A telephone ringing
  • Being in car seat when it is places on the floor
  • Being touched while asleep
  • Other children screaming
  • Loud crowds
  • TV/Radio turning on/off

If you aren’t sure when your newborn is demonstrating the startle reflex, look for him to quickly extend his arms and legs, and lift his neck when asleep. This may or may not also be followed by a short cry, before he is quickly quiet and back to sleep.

Generally this reflex will be apparent at birth and will generally disappear by the time your newborn is 6 months old. It can often be seen in premature babies born after week 28, as one of their first infantile reflexes.

As always, if you are concerned about any movements your baby is making, go see your pediatrician. Likewise, if you are unsure that your baby has the startle reflex, as the pediatrician at your next visit.

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