That advice comes from the National Institute of Child Health and Human Development (NICHD), a branch of the National Institutes of Health (NIH).
The number of infants who die of SIDS rises during the winter, notes an NICHD news release.
"During these colder months, parents often place extra blankets or clothes on infants, hoping to provide them with more warmth. In fact, the extra material may actually increase infants' risk for SIDS," states the release.
"Unless there's a medical reason not to, infants should be placed on their backs to sleep, on a firm mattress with no blankets or fluffy bedding under or over them," the release continues.
"If a blanket is used, it should be placed no higher than the baby's chest and be tucked in under the crib mattress. The baby's crib and sleep area should be free of pillows and stuffed toys, and the temperature should be kept at a level that feels comfortable for an adult," states the release.
SIDS is the sudden, unexpected death of an infant who is less than 1 year old with no explanation for the baby's death after a thorough investigation.
Although rare, SIDS is the leading cause of death in infants between 1 month and 1 year of age. Every year, about 2,500 U.S. babies die of SIDS, according to the NICHD.
Most SIDS cases happen when babies are 2 to 4 months old, states the NICHD.
SIDS cases have dropped by more than half since SIDS education campaigns began more than a decade ago. However, SIDS is still more common among minorities than among whites, notes the NICHD.
Tips to Help Prevent SIDS
The American Academy of Pediatrics recently updated its recommendations on SIDS prevention. The updated guidelines, which appeared in the November 2005 issue of Pediatrics, are:
Always place your baby on his or her back to sleep -- for naps and at night.
Place your baby on a firm sleep surface, such as on a safety-approved crib mattress, covered by a fitted sheet.
Keep soft objects, toys, and loose bedding out of your baby's sleep area.
Do not smoke or allow smoking around your baby.
Don't share your bed with your baby during sleep. Keep your baby's sleep area close to, but separate from, where you and others sleep.
Consider offering a clean pacifier when placing your baby on his or her back to sleep.
Don't let your baby overheat during sleep.
Avoid products that claim to reduce SIDS risk. Effectiveness and safety of these products have not been thoroughly tested.
Don't use home monitors as a way to reduce SIDS risk. There is no proof that these monitors decrease the occurrence of SIDS.
Reduce the chance that flat spots will develop on your baby's head by providing "tummy time" when your baby is awake and someone is watching, changing the direction that your baby lies in the crib, and avoiding too much time in car seats, carriers, and bouncers.
Recently, British researchers warned that parents shouldn't share a couch with a baby during sleep, either.
SOURCES: News release, National Institute on Child Health and Human Development. American Academy of Pediatrics' Policy Statement, Pediatrics, November 2005. WebMD Medical News: "New Tip to Help Babies Avoid SIDS."
Reviewed by Ramaz Mitaishvili, MD