Your baby's startle reflexes will begin to disappear as they grow. By the time your baby is 3 to 6 months old, they probably won't demonstrate the Moro reflex any longer. They'll have more control over their movements, and their reflexes will become less jerky.

How do you know when startle reflex is gone?

Once the neck can support the weight of the head, at about 4 months of age, babies start having fewer and less intense Moro reflexes. They might only extend and curl the arms without moving the head or legs. The Moro reflex disappears completely when the baby is 6 months old .

How long does the startle reflex last?

Startle reflexes can be observed in the womb, are present at birth, start to fade by 12 weeks and will likely disappear by 4 to 6 months. Other reflexes show up a few days after birth and stop sooner.