ANAHEIM — A report presented this week to scientists here concludes that many babies whose deaths have been linked to Sudden Infant Death Syndrome may have suffocated by lying face down on cushioned bedding, such as comforters and sheepskin rugs.
In the report delivered at the annual meeting of the Federation of American Societies for Experimental Biology, Drs. James Kemp and Bradley Thach, pediatricians at the Washington University School of Medicine in St. Louis, said infants should sleep on firm, flat mattresses with as little underneath them as possible.
The researchers also found that it is better for the infants to sleep in positions other than on their stomachs.
"Perhaps one in four of sudden, unexplained infant deaths may be explained by exhaled carbon dioxide being trapped around the baby's face by bedding such as pillows, comforters and foam beds," Kemp said.
But according to Phipps Cohe, public affairs director at the SIDS Alliance in Maryland, the materials tested by the researchers are hardly ever used.
"They are not talking about a mattress and a crib," Cohe said. "These beanbag-type materials are not typically used."
Cohe said the study reinforces normal recommendations to parents to put infants to sleep on firm, flat mattresses.
Maura Davis, a spokeswoman for the Juvenile Products Manufacturers Assn., makers of baby furniture, also said the materials used in the study were not "traditional, juvenile bedding."
Davis said the association has always recommended that "infants should never be put to sleep on adult beds, pillows, cushions or rugs."
The unpublished report is an expansion of a previous study by the same researchers, who demonstrated the suffocation hazard of infant beanbag cushions filled with polystyrene beads.
SIDS kills about 7,000 infants annually in the United States. Many causes have been proposed but none proven.
The types of bedding used in the Kemp-Thach study were a synthetic-filled adult pillow, a 3 1/2-inch-thick foam couch cushion, a 1 1/2-inch-thick foam pad covered with a comforter, a sheepskin sold as an infant bed and a soft infant bassinet cushion covered by a blanket.
Elaine Tyrrell, spokeswoman for the U.S. Product Safety Commission, said the agency received reports of more than 250 infants suffocating on adult or youth mattresses or water beds in 1985-90, the latest available figures.
Thach and Kemp said worldwide studies indicate that at least one-fourth of presumed SIDS victims were found face down in bedding and should be investigated as possible suffocation deaths.