CHICAGO – Federal regulators and the nation’s leading pediatrician group on Wednesday warned parents that popular baby ‘sleep positioners’ — marketed as safety products — can be deadly and urged families to stop using them, retailers to stop selling them and manufacturers to stop making them.

The products have been linked to at least a dozen suffocation deaths in the last 13 years, regulators said. The products often have foam bolsters on the sides that help keep a baby in one position, but infants can wiggle or roll into unsafe spots. Babies have suffocated on the foam or become trapped between the product and the side of the crib.

For years, the American Academy of Pediatrics and others have promoted scientifically backed advice calling for babies to sleep on their backs to reduce the risk of sudden infant death syndrome, or SIDS. The sleep positioners appeal to parents who worry a child will stray from that position. Sales of the products took off in the last five years.

Although the warning does not constitute a ban, Dr. Joshua Sharfstein, a pediatrician who is the No. 2 official at the Food and Drug Administration, said many of these products are “illegal devices” because they tout their ability to reduce the risk of SIDS. The positioners, he said, have not been cleared for that use.

There is no evidence that they prevent SIDS, said Dr. Rachel Moon, chair of the American Academy of Pediatrics SIDS Task Force.