Lynn Craig puts three electrodes on a sleeping baby's head and a tube in the infant's ear that emits clicking sounds.
Craig, obstetrics and pediatrics manager at Parkland Health Center in Farmington, Mo., and her colleagues used a machine designed to test for auditory brainstem response on each of Parkland's 430 newborns last year because Missouri is one of 38 states that require hospitals to perform hearing screenings.
"It not only tells us if the baby hears the clicks but it tells us if the baby's brain acknowledges what it's hearing," said Craig, who has identified three children who were completely deaf using the machine since Missouri's law took effect in 2002.
"We have also seen quite a few kids with devastating hearing loss that would not have been picked up until three or four years later," Craig said.
Each year 12,000 American babies are born with hearing loss, making it the most common birth defect in the country, according to the National Center for Hearing Assessment and Management. Early intervention and hearing aids for babies just a couple of months old can make a difference. A University of Colorado study found that children diagnosed early and fitted with hearing aids were speaking at their age level by 3 years old.
As state screening laws have become more common, the number of newborns tested has grown substantially. Last year 86 percent of U.S. newborns were screened for hearing loss compared to 25 percent in 1999, according to the National Campaign for Hearing Health.
Despite significant progress in the past five years to detect deafness in babies, laws in 12 states are silent on screening, leaving some families on their own to diagnose hearing loss, often when a child doesn't speak at the same age as others.
States without mandatory newborn testing are Alabama, Alaska, Arizona, Delaware, Idaho, Michigan, Minnesota, North Dakota, South Dakota, Tennessee, Vermont and Washington. Screening does happen in some of those states, however. For example, Idaho tested 97 percent of newborns last year because all of its hospitals perform screening, and North Dakota tested 91 percent in 2002 with help from a federal grant.
Ohio, which tested just 22 percent of newborns in 2003, is the latest state to add a requirement for hearing tests for all newborns starting June 30.
Advocates of newborn screening say it costs more than $1 million in tax money for each deaf child to receive special education, but early detection can drastically pare those costs.
"If they can detect early, and parents get cochlear implants for a deaf child to hear or get hearing aids--which leads to communication which leads to education--then it's not special education, and these kids are mainstreamed," said Susan Greco, executive director of the Deafness Research Foundation, which sponsors the National Campaign for Hearing Health and its annual report card on U.S. newborn screening. The group's next report is expected May 5.
The American Academy of Pediatrics, the American Academy of Audiology, the Joint Committee on Infant Hearing and the National Association of the Deaf have endorsed newborn screening.
State officials said federal grants have helped increase screening rates. North Dakota screened 91 percent of newborns in 2002 thanks to a Maternal and Child Health Bureau grant that helped hospitals buy screening machines, said Sue Burns, a nurse and program administrator for Children's Special Health Services in North Dakota.
Mandatory screening identifies newborns with hearing loss, but it doesn't always mean that infants get treatment. California claims to be among the leaders in tracking followup treatment.
California, whose testing law took effect in 1998, emphasizes treatment through state-run "hearing coordination centers" that serve children with hearing loss, said Hallie Morrow, program medical consultant for the state's Department of Health Services. Only 57 percent of California newborns received hearing tests last year.
"We decided in California that screening is not the hardest piece of the puzzle, that followup and identification was a much more critical piece because it's more difficult to coordinate. We didn't want to set up a system that just screened all the babies, because what's the point of screening if you never make it through diagnosis? The whole point of the program is not to see how many babies you can screen but to identify babies with hearing loss early," Morrow said.
This year an Oregon law authorized its Human Services Department to use federal funds to go a step beyond screening by tracking infants who don't pass a hearing test at birth.
The Centers for Disease Control, working with state officials, has developed national goals for newborn hearing, including that every state maintain a tracking and surveillance system. Identified infants would be referred to medical, audiologic and educational services.