Newborn Hearing Test May Predict SIDS

By Miranda Hitti
WebMD Health News Reviewed by Louise Chang, MD

July 27, 2007 -- A preliminary study suggests that it might be possible to screen newborns for SIDS risk with a hearing test.

SIDS (sudden infant death syndrome) is the sudden death of an infant less than 1 year of age that cannot be explained after a thorough investigation. It's the leading cause of death among U.S. infants aged 1-12 months, according to the CDC.

The new SIDS study, published online in the journal Early Human Development, comes from researchers including Daniel Rubens, MBBS, of Children's Hospital & Regional Medical Center in Seattle.

They studied the newborn hearing test results of 31 Rhode Island babies who later died of SIDS.

Those babies had worse hearing in their right ear -- at three different frequencies -- than a comparison group of newborn babies who didn't die of SIDS, according to the study.

Rubens' team doesn't know whether the babies' hearing had anything to do with their SIDS risk.

For instance, the study doesn't show whether the babies were sleeping on their backs, which reduces SIDS risk, or whether they had other SIDS risk factors.

However, Rubens and colleagues note that inner ear damage that occurs around the time of birth might increase SIDS risk. The researchers reason that the inner ear is involved in maintaining infants' breathing during sleep and a damaged inner ear might hinder that process.

If their theory proves correct, that would mean that newborn hearing tests may help screen for SIDS risk.

"This discovery opens a whole new line of inquiry into SIDS research," Rubens says in a news release.

"For the first time, it's now possible that with a simple, standard hearing test babies could be identified as at risk for SIDS, allowing preventative measures to be implemented in advance of a tragic event," Rubens says.

The findings don't prove that hearing tests will identify babies at risk for SIDS. So the researchers plan further studies to investigate what they describe as a "potential association" between inner ear damage and breathing control.

"We must now fully explore all aspects of inner ear function and SIDS, and analyze testing frequencies higher than those currently tested by newborn hearing screen centers," Rubens says.

Since scientists don't yet know exactly what causes SIDS, they don't have a guaranteed way to prevent SIDS.

But it is possible to reduce -- if not eliminate -- SIDS risk. Here are 11 tips from the American Academy of Pediatrics to reduce SIDS risk:

• Always put babies to sleep on their backs -- for naps and at night.
• Place the baby on a firm sleep surface, such as on a safety-approved crib mattress, covered by a fitted sheet.
• Keep soft objects (including stuffed toys) and loose bedding out of the baby's sleep area.
• Don't smoke while you're pregnant.
• Don't smoke or allow smoking around your baby.
• Don't share your bed or couch with your baby during sleep.
• Consider offering your baby a pacifier at nap time and bedtime.
• Don't let your baby overheat during sleep.
• Avoid products that claim to reduce SIDS risk.
• Don't use home monitors as a way to reduce SIDS risk. There is no proof that those monitors decrease the occurrence of SIDS.
• Reduce the chance that flat spots will develop on your baby's head by providing "tummy time" when your baby is awake and someone is watching, changing the direction that your baby lies in the crib, and avoiding too much time car seats, carriers, and bouncers.

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