The newborn startle reflex, also known as the Moro reflex, is one of the most noticeable reflexive movements you’ll see from birth. If you’re a first-time parent, you might be startled by the startle reflex – but it’s good to see!

One second, your newborn is sleeping soundly; the next, their arms and legs jerk outward before slowly falling back down. Sometimes, it causes babies to wake themselves.

It is an automatic response to a sudden change in the baby's environment or a feeling of falling. It is a natural and normal response in newborns, and it serves an important protective function. It helps babies respond to potential dangers and prepares them for their new environment outside the womb.

As your baby's nervous system develops, they will gain more control over their movements, and the startle reflex will gradually diminish. This particular reflex typically disappears between 4 and 6 months of age.

The startle reflex isn’t something that needs fixing. It’s a normal part of your baby’s development and goes away on its own. You can swaddle your baby if they are not yet showing any signs of rolling, as this can prevent the startle reflex from disrupting their sleep. Choosing not to swaddle is okay too! Otherwise, do your best to offer comfort and reassurance when your baby seems distressed.