Many babies around the world have died as a result of Sudden Infant Death Syndrome (SIDS). In the United States, it is the most common cause of death among babies between the ages of 1 month and 12 months. Is there any way to reduce the risk? According to The Journal of the American Medical Association (JAMA), research in recent years indicates that the risk of SIDS seems to drop significantly when babies sleep on their back rather than on their stomach. Several countries have instituted programs to alert parents to the association between sleep position and SIDS. In Australia, England, Denmark, New Zealand, and Norway, SIDS fell by at least 50 percent after one to two years of public campaigns to promote putting babies to bed on their back.

Exactly how a baby’s sleeping on its stomach is linked to SIDS is not known, but some researchers suggest that this prone position may result in a baby’s rebreathing its own expelled air, thus increasing the level of carbon dioxide in its blood. The baby’s body may also become overheated because it does not dissipate heat as well when lying on its stomach. In any case, infants laid down either on their back or on their stomach tend to remain in that position. Studies also suggest that putting a normal, healthy infant on its back is better than putting it on its side.Why do mothers choose one sleep position over another? JAMA notes that mothers often just follow custom—they put their babies to bed the way their own mothers or others in their community would. Or they may adopt the practice they observed in the hospital. Some mothers also feel that their baby prefers or sleeps better in a particular position. Many mothers consistently lay the baby down on its back for the first month but then change to the stomach later on. “This trend is disturbing,” states JAMA, “because the risk of SIDS is highest among infants at 2 to 3 months of age.” Doctors are striving to inform parents of small infants about what they say is a simple, effective measure for reducing the risk of SIDS—placing healthy infants on their back to sleep.