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Understanding newborn screening tests for your baby

By January 23, 2013October 23rd, 2018No Comments



  • All babies in the United States get newborn screening. Each state decides which tests are required.
  • Ask your baby’s health care provider which tests your baby will have.
  • If your baby has a newborn screening test result that’s not normal, he should have a different kind of test to make sure he’s healthy.
  • Newborn screening helps identify rare but serious health conditions. Many of these can be treated if found early


What is newborn screening?

Before your baby leaves the hospital, he has some special tests called newborn screening. Newborn screening checks for serious but rare conditions that your baby has at birth. It includes blood, hearing and heart screening.

Your baby can be born with a health condition but may not show any signs of the problem at first. If a health condition is found early with newborn screening, it often can be treated. This makes it possible to avoid more serious health problems for your baby.

When is newborn screening done?

Your baby gets newborn screening before he leaves the hospital after birth, when he’s 1 to 2 days old. If your baby isn’t born in a hospital, talk to her provider about getting newborn screening at 1 to 2 days of age. Some states require that babies have newborn screening again about 2 weeks later.

How does newborn screening happen?

There are three parts to newborn screening:

  1. Blood test. Most newborn screening is done with a blood test. A health care provider pricks your baby’s heel to get a few drops of blood. He collects the blood on a special paper and sends it to a lab within 1 day (24 hours) for testing. Your provider gets results for serious health conditions within 5 days and results for all conditions by 7 days. Following these timeframes is critical in case your baby has a disorder that needs to be identified and treated as early as possible. You can check with the hospital staff to make sure your baby’s sample was sent to the lab on time.
  2. Hearing screening. For this test, your provider places a tiny, soft speaker in your baby’s ear to check how your baby responds to sound. Your baby gets this test before she leaves the hospital after birth.
  3. Heart screening. This test is called pulse oximetry. It checks the amount of oxygen in your baby’s blood by using a sensor attached to his finger or foot. This test is used to screen babies for a group of heart conditions called critical congenital heart disease (CCHD). Your baby gets this test before he leaves the hospital after birth.

To find out more about the timeframes used for sending blood samples to lab and getting test results back, ask your baby’s provider or the hospital staff. Some states have websites with information about how well your hospital uses the timeframes. Check your state’s health department website to see if this information is available about your hospital.

What if newborn screening results aren’t normal?

Most newborn screening results are normal. In rare cases when your baby’s screening results aren’t normal, it may simply mean she needs more testing. Your baby’s provider then recommends another kind of test, called a diagnostic test, to see if there is a health problem. If the diagnostic test results are normal, no more testing is needed. If the diagnostic test results are not normal, your provider can guide you about next steps for your baby.

If one of your children has a health condition, will another have it, too?

Almost all of the health conditions found by newborn screening are inherited. This means they are passed from parents to children.

When one child in a family has an inherited health condition, the chance of a brother or sister having the same condition is higher than if no child in the family has the condition.

If you have a child with a health condition and you want to have another baby, talk to your health care provider or a genetic counselor. A genetic counselor is a person who is trained to know about genetics, birth defects and other medical problems that run in families.

Sometimes hearing loss is not inherited. For example, it can be caused by an infection during pregnancy. In this case, it usually doesn’t happen in another pregnancy.

What kinds of health conditions does newborn screening test for?

Each state requires different tests, so ask your baby’s health care provider which tests your baby will have. You also can visit to find out what conditions your state tests for.

The March of Dimes would like to see all babies in all states screened for at least 34 health conditions. Many of these health conditions can be treated if found early. The health conditions are divided into seven groups:

1. Organic acid metabolism disorders. Babies with these problems don’t metabolize food correctly. Metabolism is the way your body changes food into the energy it needs to breathe, digest and grow.

  • Isovaleric acidemia (IVA)
  • Glutaric acidemia (GAI)
  • Hydroxymethylglutaric aciduria, also called 3-OH 3-CH3 glutaric aciduria (HMG)
  • Multiple carboxylase deficiency (MCD)
  • Methylmalonic acidemia, mutase deficiency (MUT)
  • 3-methylcrotonyl-CoA carboxylase deficiency  (3MCC)
  • Methylmalonic acidemia, CBl A and CBl B forms
  • Propionic acidemia (PROP)
  • Beta-ketothiolase deficiency (BKT)

2. Fatty acid oxidation disorders. When your body runs out of sugar, it usually breaks down fat for energy. A baby with fatty acid oxidation problems can’t change fat into energy.

  • Medium-chain acyl-CoA dehydrogenase deficiency (MCAD)
  • Very long-chain acyl-CoA dehydrogenase deficiency (VLCAD)
  • Long-chain hydroxyacyl-CoA dehydrogenase deficiency (LCHAD)
  • Trifunctional protein deficiency (TFP) Carnitine uptake defect (CUD)

3. Amino acid metabolism disorders. Babies with these problems can’t process amino acids in the body. Amino acids help the body make protein.

  • Phenylketonuria (PKU)
  • Maple syrup urine disease (MSUD)
  • Homocystinuria (HCY)
  • Citrullinemia (CIT)
  • Argininosuccinic acidemia (ASA)
  • Tyrosinemia type I (TYR I)

4. Hemoglobin disorders. These problems affect red blood cells. Red blood cells carry oxygen to the rest of the body.

5. Lysosomal storage disorders. Babies with these problems can’t break down certain types of complex sugars. This causes harmful substances to build up in the body.

  • Mucopolysaccharidosis Type-1 (MPS 1)
  • Pompe disease

6. Adrenal gland disorders. These problems affect the adrenal glands, which sit on top of the kidneys and help the body make hormones.

  • Congenital adrenal hyperplasia (CAH)
  • X-linked adrenoleukodystrophy (X-ALD)

Other disorders

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