Rolling over/ stop swaddling

Summer

Hey mamas-

My LO is 4 months. She has rolled tummy to back three times but it seemed accidental each time. Now, she rolls from back to her side in the middle of the night.

We have been swaddling her with one arm out for the past two weeks and she sleeps really well but I’m worried she will roll in the night.

When we try to swaddle her (halo 3 in 1) with both arms out she wakes up every 15 minutes because her startle reflex is still so strong.

My pediatrician said not to use products like the zipaddee zip or anything that is arms in. We don’t have a/c and it’s too hot for merlins suit.

What to do! Leave one arm out and hope she doesn’t roll in the night?!?

She sleeps in her crib in our bedroom.

Thanks in advance