It's a normal sign of a healthy nervous system and usually fades by 3–4 months. Because it can wake a sleeping baby, snug (hips-healthy) swaddling in the early weeks can help some babies sleep more soundly until the reflex settles.
Glossary
Moro reflex (startle reflex)
The Moro reflex is a newborn's startle response — arms fling out then curl back in — triggered by a sudden noise, movement or feeling of falling.
Related guides
Newborn sleep: what to expect (0–12 weeks)
In the early weeks your baby's sleep is meant to be short, scattered and feed-driven — here's what's normal and how to ride it out.
Soothing a crying baby
Crying is how your baby talks to you — check the basics first, then try a few gentle calming tricks, and remember it's okay to put your baby down safely and take a breath.
Related terms
General information, not medical advice. For concerns about your child, talk with your doctor or child-health nurse.