What Is the Moro Reflex? And How Does It Affect Newborn Sleep?

If you’ve ever watched your newborn suddenly fling their arms out, open their hands, or jerk awake while sleeping, you’ve probably seen the Moro reflex, also known as the startle reflex.

It’s a completely normal newborn reflex and an important part of early development.

What Is the Moro Reflex?

The Moro reflex is an involuntary response to a sudden sound, movement, or sensation. Your baby may suddenly extend their arms, open their hands, and then bring their arms back toward their body.

The reflex gradually fades as your baby’s nervous system develops, but during the newborn stage, it can sometimes interrupt sleep.

How Does the Moro Reflex Affect Sleep?

That sudden startle can wake your baby just as they are settling into sleep. This is one reason many parents choose to swaddle their newborns.

But does swaddling have to mean completely restricting the startle reflex?

We don't think so.

The Moro reflex plays an important role in early brain development, so letting baby experience it matters. Instead of completely preventing the reflex, Swaddelini allows your baby to experience the reflex and then soothe themselves back to sleep with a gentle hugging design that helps them settle.

For more on this, check out How Does Swaddling Help Soothe After the Startle Reflex in Babies?.

How Is Swaddelini Different?

Swaddelini is a stretchy swaddle sleep sack that gives babies a gentle, womb-like feeling of comfort without complicated wrapping.

It is the only swaddle that does not inhibit the startle reflex. Instead, its 3D-knit construction allows babies to move their arms toward their chest and midline while experiencing that natural reflex.

No Velcro. No zippers. No snaps. No wrapping.

Just a soft, stretchy hug that moves with your baby.

The Bottom Line

The Moro reflex is a normal part of newborn development. You don’t need to fear those little startles. Instead, think of them as part of your baby’s developing nervous system.

And with the right swaddle, you can give your baby the comfort without taking away their natural movement.