The American Association of Pediatrics (AAP) strongly advises us as parents against using a baby crib liner as a 2007 study said there is no evidence that it does not prevent injuries. On the contrary, said AAP, liners show a possible risk of strangulation, suffocation, and sudden infant death syndrome (SIDS). A baby crib liner or bumper is a fabric pad that is made to surround your baby’s crib interior to prevent them from falling through the slats accidentally.