Less prone sleeping (lying face down) has resulted in lower SIDS rates. Although the cause of SIDS is not certain, one explanation may be that SIDS infants asphyxiate when they rebreath exhaled air containing an increased amount of carbon dioxide. When a baby sleeps in a prone position, he may often have an arm at the side of his head that creates a pocket of air, laden with carbon dioxide, around the baby’s face. Bedding may contribute to the formation of these pockets of carbon dioxide.

In a study of five commercial sleep products, researchers at Saint Louis University examined new bedding products that claim to reduce the rebreathing risk for prone infants. They found that all but one system said to prevent rebreathing, did little to reduce and might even worsen carbon dioxide trapping.

“Some of these product claims might lead parents to think that it is safe to put their babies in prone positions,” said researcher James S. Kemp, M.D., assistant professor of pediatrics at Saint Louis University School of Medicine and pediatrician at SSM/Cardinal Glennon Children’s Hospital. “If this exposed them to greater risk and resulted in SIDS, it would be dreadful.”

Working with colleagues at Minneapolis Children’s Hospital, Dr. Kemp tested two active systems The Halo Sleep Systems and the Sleep Guardian and three passive systems Breathe Easy, Bumpa Bed and Kid Safe Baby Air Products were analyzed for their ability to hasten carbon dioxide dispersal using a biomechanical model of a mannequin placed face-down on a test surface ventilated with a syringe containing five percent carbon dioxide. Each product was tested in three simulations with the face down and underlying cover 1) taut, 2) wrinkled and 3) taut but with the mannequin arm at the side of the head.

No product in the study completely prevented rebreathing, but the Halo Sleep System maintained lower carbon dioxode dispersal rates. All systems exceeded thresholds under one or more simulations, except the Halo System.

Impassioned by having lost a child to SIDS himself, the developer of the Halo System is an engineer, familiar with ventilation. Using a fan to increase air movement, he made it with enough circulation, so that if the baby put his arm up, air would not be trapped by his face. Dr. Kemp said that since it is priced at around $200, it may be more for parents who can afford it and feel particularly concerned about their child’s risk of SIDS.

Researchers found that most other models were poorly designed and not tested. They recommended that industry standards for rebreathing based on biomechanical models should be developed.

“No one would recommend that a baby sleep on this stomach, regardless of how effectively the bedding moves air,” said Dr. Kemp. “And those that make claims without proper testing, do parents a disservice. We hope that the Consumer Protection Agency will begin to regulate these products, before someone gets hurt.”