If you plan on using toddler’s bedding within your baby crib, even if the dimension of the crib sheets is the same, some extra safety precautions must be taken. 

First, babies don’t sleep with pillows, top crib sheets, or blankets, so they might want to keep them until their child is old enough. 

Also, the crib sheets should fit snugly onto the mattress, without loose corner; otherwise, they become a SIDS risk for your baby. It never happens to me, but some of my friends had problems with sheets who shrink after being in the washer, so make sure to read (and follow) the laundry instruction on the label.