Assure yourself that all guide rods and support brackets are firmly in place and secure, and that no screws are missing. Check the locks and latches on the crib. They should be smooth, and tight enough to prevent accidental release. Be certain the paint used on the crib is lead-free. If it isn't, the old paint should be removed.
Some babies do chew on their cribs, and ingesting lead can cause brain damage.
If your crib is new, remove and discard all plastic packaging materials, including the thin plastic mattress cover. As with a used crib, check the guide rods, support brackets, locks, and latches, and make sure no screws are missing. With any crib, new or old Place the crib out of reach of any cords, electrical sockets, or other hazards. Keep crib rails up at all times when the baby is unattended. As soon as your baby can pull himself or herself up, move the mattress to the lowest position.