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Newborn Metabolic Screening

Most babies look healthy and perfect when they are born—just ask their parents.

Newborn and mother

But because some potential problems aren't readily seen, all newborns are tested for certain conditions, including metabolic disorders.

A metabolic disorder is one that gets in the way of how the body breaks down food or absorbs nutrients. Left untreated, some of these disorders could affect a baby's development. They can cause organ damage or even death.

By screening for these disorders at birth, healthcare providers are then able to treat them as soon as possible. In many cases, simply finding out that your baby has the condition and making diet or lifestyle changes will allow your child to cope with the metabolic disorder and live a healthy life.

One of these disorders is known as phenylketonuria, or PKU. The blood test for PKU finds out if your baby's body can process a substance called phenylalanine. Many foods contain phenylalanine. If your baby's body cannot process it, it can build up in his or her blood and tissue. Undiagnosed, PKU can cause permanent brain damage.

If PKU is caught during the screening process, your baby can be placed on a special diet. This will help your baby avoid complications. This is just one example of how important metabolic screening can be.

Hypothyroidism is another condition that can be caught by a newborn metabolic screening. With this disorder, your baby's body does not make enough thyroid hormone. By catching it early, the healthcare provider can put your baby on a thyroid medicine to help prevent any complications.

Not every disorder is as easily treatable as PKU or hypothyroidism. In all instances, though, it's important for you to know about any conditions your baby has so that you can take all necessary health steps.

What happens during a metabolic screening

There is no national standard for metabolic screening programs. Each state sets its own rules. You can rest assured, though, that these tests will not harm your baby. Most of them need just a few drops of blood taken from the baby's heel before your baby is discharged from the hospital.

This blood sample is then sent to a lab, where it is screened for many disorders at once. Besides PKU and hypothyroidism, other common metabolic disorders looked for in a newborn screening are galactosemia, sickle cell disease, cystic fibrosis, and toxoplasmosis.

In some states, the healthcare providers may request that your baby be screened a second time. This second testing usually happens about 2 weeks after birth during a follow-up appointment with your healthcare provider.

Both you and your healthcare provider are notified if your baby's newborn screen results are positive within the first few weeks of life. 

The importance of metabolic screening

Experts agree that the benefits of newborn metabolic screening outweigh any risk. Newborn metabolic screening helps both parents and society as a whole. For many diseases, such as PKU, catching them early on means you can make dietary changes to make sure that your baby lives a healthy, normal life.

As a parent, the best thing you can do is stay informed. Before your baby is born, ask your healthcare provider about the tests that will be done and what choices are available should one of them come back positive. 

Medical Reviewers:

  • Adler, Liora C., MD
  • Freeborn, Donna, PhD, CNM, FNP