Soft bedding can make cribs deadly.

An estimated 7-9,000 infants mysteriously will die in their cribs this year. The fatalities will be attributed to Sudden Infant Death Syndrome (SIDS), but researchers at the Washington University School of Medicine indicate that some of those children will die because of how they slept and the bedding they slept on.

Hundreds of deaths might be avoided each year if reliable guidelines are developed to identify infant bedding material that could be dangerous due to its softness. More reliable quantitative ratings are needed for bedding products, according to James S. Kemp, assistant professor of pediatrics, and Bradley T. Thach, professor of pediatrics. Their study of the problem of rebreathing, a form of accidental infant suffocation, has helped lead to the banning of polystyrene-filled cushions by the Consumer Product Safety Commission and was cited by the American Academy of Pediatrics when making their recommendation that infants sleep on their backs or their sides. Infants face-down on polystyrene-filled cushions and in soft bedding material can breathe in air that becomes trapped around the face. This rebreathing of carbon dioxide can lead to accidental suffocation of infants.

Malleability of bedding is a major factor in the dispersal of air that is potentially harmful to sleeping infants, Kemp explains. "If a baby lifts its head off an item of bedding, and the mattress springs up, it's less likely that carbon dioxide will remain trapped. If the bed retains a little |sink hole' beneath the baby's face, it will be more likely that bad air will be trapped."

Mattress safety is not the only...