Health Topics for Child Health and Development

UI Children's Hospital

UI Family Care Centers

Divisions Within the Department of Pediatrics

Iowa Registry for Congenital and Inherited Disorders

Newborn screening tests

Screening tests for newborns are done at birth to reveal inherited disorders. Babies affected by these diseases may look normal at birth and may continue to look normal for days or weeks. By the time a baby with one of these disorders looks sick, brain and nerve damage may have already begun. A baby has the best chance for normal development when a disorder is found within the first few days of life.

The first screening test is not a blood test. It is called the Apgar test. It is performed 2 times, once in the first minute of life and again at 5 minutes. This is a series of tests that assess the general health of the newborn. Areas evaluated include heart rate, breathing function, muscle tone, response to stimulation, and color. The results determine the immediate care to be given.

The screening tests that follow require blood or urine samples. In the United States, all states require screening for phenylketonuria (PKU) and congenital hypothyroidism. A majority of states screen for galactosemia and hemoglobin disorders. Less than half of the states screen for maple syrup urine disease, homocystinuria, and biotinidase deficiency.

Descriptions of the 3 most widely screened diseases follow:

• Phenylketonuria (PKU) is caused by a baby's inability to use the amino acid phenylalanine. If not treated early, PKU leads to brain damage, nerve damage, and mental retardation. A baby can develop normally when a special low-protein diet is started in the first weeks of life.

• Congenital hypothyroidism is caused when a baby is born without enough thyroid hormone. This condition can lead to poor growth and mental retardation. Normal growth and development can result from giving the baby extra thyroid hormone as soon as possible after birth.

• Galactosemia is caused when a baby cannot digest galactose, a sugar found in milk. The disorder leads to cataracts, liver damage, mental retardation, and death. A special formula is given to prevent these symptoms.

About 1 out of 1,000 infants are born deaf or with severe hearing loss. Infant hearing loss is screened for in the newborn when indicated and again at 3 months of age. If needed, therapy can begin before 6 months. If not detected before age 2, deafness will interfere with the child's speech and language skills. Infant screening tests for hearing are quick and simple.

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