Why do babies sleep with hands up?
Olivia Owen
Updated on January 05, 2026
It's Part Of Their Moro Reflex
If you've ever witnessed your sleeping baby suddenly startle and fling their arms up in the air, then you've seen the Moro reflex in action. As explained in a study of the same name, the Moro reflex is a completely normal reflex in full-term babies.Is it OK for babies to sleep with arms up?
Arms-up position is great for self-soothing. Transition at the first sign of rolling, likely 3-6 months. Please don't put anything in the crib at all—blankets, toys, bumpers, etc. They can't keep them away from their face before one year.Why babies keep their hands up?
Their fists are clenched, with arms bent and legs held close to their body. This typically isn't anything to worry about — it's the natural fetal position they've been used to in the womb. But you may start to wonder why your baby clenches their hands so much.What do autistic babies do with their hands?
A child at risk for autism might move their hands, fingers, or other body parts in an odd and repetitive manner. Some examples are: arm flapping, stiffening arms and/or legs, and twisting of wrists.How can you tell if a baby has autism?
Recognizing signs of autism
- May not keep eye contact or makes little or no eye contact.
- Shows no or less response to a parent's smile or other facial expressions.
- May not look at objects or events a parent is looking at or pointing to.
- May not point to objects or events to get a parent to look at them.
What do movements during sleep in kids indicate? - Dr. Shaheena Athif
Why does my baby always have her arms up?
Early reflexesThe startle reflex (or Moro reflex) is present in most young infants until they reach around 3 months old. If your baby is startled by a loud noise, large motion, or anything else, you may notice that both arms fly upward or outward before coming down again, often in a jerky fashion.