Your baby's crib should be lowered by half a notch, or even an entire notch, once they're able to sit up.
This usually happens between 5 and 8 months of age. Once your baby can pull up on their own you should adjust the mattress to its lowest setting for your baby's safety. Falls are the most common injury associated with cribs, even though they are the easiest to prevent. Children are most likely to fall out of the crib when the mattress is raised too high for their height, or not lowered properly as they grow.
Highest Crib Setting
This setting is usually best for newborns who aren't going to move around much. Many times, babies are still in a sleep sack or a swaddle when they're at this mattress setting. This is usually the setting parents use when they transition their baby from the bassinet to the crib.
Middle Setting
At this point, your baby can move around, but can't stand up on his or her own. The exact time you'll need to switch to this setting will depend on how fast your baby grows.
Lowest Crib Setting
This is the setting you should be eyeing when your baby shows he or she can stand up on his or her own or at least push up on his or her own. You never know when they'll get to the next stage and try to make their way over the rails when you're not looking. Babies are pretty fearless, so you want to be one step ahead of them all of the time.
Source https://momlovesbest.com/ ; https://www.familyeducation.com/; https://www.healthychildren.org/
