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.

When do jerky movements stop in babies?

These reflexes are involuntary movements that are a normal part of infant development. These early reflexes gradually disappear as babies mature, usually by the time they are 3–6 months old.

How do you stop the startle reflex without swaddling?

For parents who do not want to swaddle, simply placing their baby's head down extra gently can help them avoid the Moro reflex.