The Most Common Birth Defect
Beth Trama, of Smithtown, New York, was watching her son, Luca, sleep peacefully in the hospital nursery, when the newborn next to him let out a loud, high-pitched scream. Luca didn't wake up. Trama couldn't believe that the noise didn't startle him, but she assumed he'd just gotten used to being with all those crying babies -- until he failed his hearing screening the next day.
You're probably surprised to find out that hearing loss is the most common birth defect. Every day, about 33 babies are born in the U.S. with a hearing impairment. But the news hasn't gotten through to parents -- in fact, only 1 percent of new and expectant moms ranked hearing loss as their top concern about their child's health, according to a survey by the Alexander Graham Bell Association for the Deaf and Hard of Hearing, in Washington, D.C.
A Recessive Gene
Many parents figure their baby isn't at risk if they don't have a history of deafness in their family. However, about 90 percent of deaf children are born to hearing parents. Deafness can be caused by a dominant gene -- meaning one or both parents are deaf -- or by a recessive gene, so a child can inherit the trait even if no family members are hearing-impaired. That's what happened to Luca. After his diagnosis, doctors discovered that both of his parents had a recessive gene for a genetic disorder that damages the hair cells in the inner ear so they can't carry sound to the auditory nerve. As a result, Luca is severely deaf in both ears.
Hearing loss can also be caused by many nonhereditary factors, including infections, prematurity, severe jaundice, or a lack of oxygen during delivery, says Ellen M. Friedman, MD, chief of pediatric otolaryngology at Texas Children's Hospital, in Houston. Unfortunately, most of these causes aren't preventable.