Letting your baby suck on a pacifier before bed may help reduce the risk of sudden infant death syndrome (SIDS).

That's the conclusion of a review of studies done on pacifier use. And the evidence was compelling enough for the American Academy of Pediatrics (AAP) to include a recommendation about pacifier use in its updated SIDS guidelines.

"When we looked at the last time the baby was placed for sleep, there was a consistent protective effect for SIDS from pacifier use," said study author Dr. Fern Hauck, an associate professor of family medicine and public health sciences at the University of Virginia Health System in Charlottesville, Va.

"There was a 61 percent reduction in SIDS risk [from pacifier use]," said Hauck.

Results of the study, along with the new guidelines, were to be presented Monday at the AAP's National Conference and Exhibition in Washington, D.C.

Hauck and her colleagues reviewed seven studies that looked at the association between pacifier use and SIDS. They concluded that approximately one SIDS death could be prevented for every 2,733 babies who use a pacifier while they sleep.

That benefit, said Hauck, outweighs any potential risks of pacifier use, including dental problems, a slightly increased risk of ear infections and breast-feeding difficulties.

Hauck said she didn't know why pacifier use might protect against SIDS, but said there are several theories. One is that sucking on a pacifier brings the tongue forward and forces the airway to open more. Another is that when babies suck on a pacifier, they may be more easily aroused from sleep.

Dr. Dan Polk, vice chairman of the division of neonatology at Children's Memorial Hospital in Chicago, said this study's findings may be reassuring to parents who already give their infant a pacifier. But, he said, the findings only prove an association between pacifier use and a reduced incidence of SIDS, not necessarily a cause-and-effect relationship. These findings don't, he said, prove that pacifier use can actually reduce SIDS.

Whatever the reason for the apparent protective effect, the AAP is recommending offering infants a pacifier at bedtime and naptime for the first year of life. The pacifier doesn't need to be reinserted if it falls out during sleep. And don't coat the pacifier with any sweet substances to entice the baby to take it. Breast-fed infants should not be given a pacifier until breast-feeding is well-established, usually at one month, the academy said.

Along with endorsing pacifier use, other big changes in the AAP SIDS guidelines include recommending that babies sleep in the same room as the parents, though not in the same bed, and that parents don't put their babies to sleep on their sides.

"There's been a lot of new information on SIDS in the past five years, which is why the committee revised the SIDS guidelines," explained Dr. Rachel Moon, a pediatrician and SIDS researcher at Children's National Medical Center in Washington D.C.

Other key recommendations for preventing SIDS include:

• Place infants to sleep on their backs every time they go to sleep.
• Only use firm sleep surfaces and keep soft objects, such as pillows and heavy blankets, out of baby's crib.
• Give baby a smoke-free environment both before and after pregnancy.
• Don't share your bed with your baby, but if possible, keep the baby in a crib in your bedroom.
• Avoid overheating your baby. Babies shouldn't feel hot to the touch. Keep the room warm enough so a lightly clothed adult would be comfortable.

The AAP committee also said parents shouldn't use commercial products marketed as reducing the risk of SIDS or home monitors. There's no evidence such products provide any benefit.

Also, the committee recommended that babies be given plenty of tummy time when they're awake to avoid the development of a flat spot on the back of the head from always sleeping in the same position.

"Parents need to make sure that it's not just them following the guidelines, but everyone caring for the baby needs to be aware. The babysitter, the grandparents, everybody needs to know," said Moon.

"Since we don't know the cause of SIDS, the best we can do is try to control the markers," said Polk. "Just do the best you can, but that doesn't guarantee you've eliminated the risk of SIDS," he added.

The results of the new study, as well as the new guidelines, will also appear in the November issue of the journal Pediatrics.