Bumpers may make your crib look more stylish, but they're not safe for babies. The American Academy of Pediatrics (AAP) suggests avoiding very thick, cushy bumpers, because your baby could suffocate if she rolls into them. If you do decide to use a bumper, pick one that's thin, firm, and well-secured at all four corners of the crib, as well as in the middle of each side. You should also stop using it by 3 or 4 months, before your baby is rolling over or, later, standing up (some babies figure out how to climb them and can topple out of the crib). Don't worry about your baby banging her head on the sides of the crib -- their heads are built to withstand the inevitable tumbles that come with learning to crawl and walk and stand.