Put your baby on his or her back to sleep.
Since 1994, that's been the dominant message of national campaigns aimed at protecting babies younger than 1 from dying suddenly in their sleep.
Yet for nearly a decade, most infant-safety advocates have realized that even though "back to sleep" reduced the SIDS rate by up to 50 percent, it isn't enough to prevent the deaths of some 4,000 babies each year.
This week, the nation's pediatricians formally updated guidelines for infant sleep safety and SIDS risk reduction to reflect evolving understanding that many factors beyond facedown sleeping contribute to baby deaths.
For the first time, the American Academy of Pediatrics specifically calls for expanding the educational campaign aimed at parents and caregivers "to include a major focus on the safe sleep environment and ways to reduce the risks of all sleep-related infant deaths, including SIDS, suffocation and other accidental deaths."
The recommendations particularly discourage adults sharing a bed with an infant, noting no studies have shown such behavior offers any protection from SIDS or suffocation.
An earlier version of the guidelines, issued in 2005, had said bed sharing was not recommended, and "may" be dangerous, but took no stronger stand out of concern that it might impede breastfeeding.
The new guidelines continue to advocate breastfeeding and suggest that parents share a room with their baby, but not a bed. They also advise against using bumper pads around the edge of a crib, which increase the risk of suffocation.
And they urge parents to immunize their infants on schedule. While some SIDS parents have pointed to shots as a possible cause of their baby's death, research indicates infants who are properly immunized are 50 percent less likely to die than those who are not.
"As a health care community, we need to do a better job translating what the research identifies as 'best practice' into the day-to-day practice of caring for infants both in the hospital and at home," said Dr. Rachel Moon, a veteran infant safety researcher at Children's National Medical Center in Washington who heads the AAP's SIDS Task Force and was the lead author of the new guidelines.
"Our goal is to ultimately eliminate these deaths completely," Moon said.
Most researchers believe that all babies risk suffocation when sharing a bed with someone else or sleeping on soft surfaces or with heavy covers or pillows, but that some infants may also have brain or heart anomalies making them particularly likely to die if their breathing is challenged or they overheat.
Evidence confirming that most deaths take place in dangerous sleeping environments has been gradually accumulating, slowed by inadequate investigations and a diagnostic bias toward default diagnosis of SIDS in many parts of the country, a problem highlighted by a Scripps Howard investigation five years ago.
A pilot program run through the federal Centers for Disease Control and Prevention, under way for several years, is using child death review committee records and other data from seven states to start a registry of infant deaths to better spot risk patterns It should yield some findings soon.
Analysis of more than 6,000 infant death investigations done several years ago by the National Center for Child Death Review showed that 43 percent of the babies were sleeping in an adult bed, only 17 percent were in a crib and 62 percent were on an unsafe sleep surface.
A number of small studies in recent years, including one presented at the AAP national meeting in Boston, have revealed that unsafe sleep conditions, including co-sleeping with an adult or another child and sleeping someplace other than a crib, are a factor in 70 to 80 percent of infant deaths.
In a related development, the Food and Drug Administration this week issued a special warning to parents against using baby monitors, infant positioners, crib tents or other devices marketed to prevent or reduce the risk of SIDS. The AAP guidelines also warn against their use.
FDA has never approved any medical device for that purpose and is warning manufacturers to stop making such claims. "These products are absolutely not necessary and they can be very dangerous," said Dr. Susan Cummins, chief pediatric medical officer for the agency's Center for Devices and Radiological Health.
The FDA has reports of 13 infant deaths associated with the use of sleep positioners -- slings or pillows that are supposed to keep babies on their backs. The Consumer Product Safety Commission has additional reports of babies found in hazardous positions after being placed in a positioner.