WASHINGTON (March 12, 2010)—The U.S. Consumer Product Safety Commission said Friday it has investigated at least 13 deaths associated with sling-style infant carriers and says it is now advising parents to be cautious when using them for babies younger than four months.

The agency says babies can suffocate when a sling's fabric presses against their noses and mouths, blocking breathing and suffocating babies within a minute or two.

Also, in cases in which slings keep infants in curled positions, bending the chin toward the chest, airways can be restricted, limiting the oxygen supply.

In those instances, babies won’t be able to cry and can slowly suffocate, the CPSC said.

Many of the infants who died in slings were either low-birth-weigh twins, were born prematurely or had breathing issues such as colds.

The CPSC said it’s urging parents of preemies, twins, babies in fragile health and those with low weight to use extra caution and consult pediatricians about the use of the slings.

The agency recommends that parents and caregivers ensure that infants’ faces aren’t covered and are visible at all times to the person wearing the sling.

If babies are nursed while in slings, their positions should be changed after feeding so their heads are facing up and are clear of the sling and their mothers’ bodies, the agency said