When should I discontinue use of the underarm snaps?

In general, you can use the underarm snaps for babies up to 6 months of age. Please keep in mind that the underarm snaps are to be used to ensure a snug fit around the upper body. When the sleep bag feels tight around the chest, you can discontinue the use of the underarm snaps. If you are unsure if your child still needs the snaps, you can try unfastening one or both sides during a nap. This will allow you to monitor the fit while your baby sleeps.