These days, most parents put infants to sleep on their backs, successfully cutting the death rate from sudden infant death syndrome by 44% since 1992. Now, a study has found that even one lapse from this routine can increase a baby's risk of death.
As part of a three-year study, Kaiser Permanente investigators questioned mothers of 185 infants who died of SIDS and 312 randomly selected moms of healthy babies in 11 California counties. Unlike earlier studies, which were mostly done overseas, the California mothers represented racially and culturally diverse groups.
The study confirmed that a baby placed stomach down is in the most danger -- the risk of SIDS is 2 1/2 times that of a baby sleeping on his or her back. And a baby placed on a side is twice as likely to die as a baby on his back.
But in the most surprising finding, the researchers said that when babies are accustomed to sleeping on their backs and are placed either face down or on the side, SIDS risk increases eight times over that of babies consistently placed on their backs.
"The problem for side sleepers is that there's a good chance they will roll onto their stomachs," says Marian Willinger, a coauthor of the study and special assistant for SIDS at the National Institute of Child Health and Human Development in Bethesda, Md.
"Every night counts. Just because you put your baby in the back position most of the time, the one night you don't do it and put them on their side or stomach puts them at greater risk of dying," says Willinger.
According to the most recent figures from the National Center for Health Statistics, 2,523 infants died of SIDS in 2000. The study was published in the March issue of the journal American Journal of Epidemiology.