Health Screenings for Babies

Soon after birth, your baby may be screened (tested) for certain genetic metabolic disorders. There are at least 400 of these diseases, which can vary in seriousness from no symptoms to severe physical or mental handicaps. Some of the disorders require treatment, while others need no care at all.

About one child in 1,000 is affected by an inherited metabolic disorder. The disorders are caused by abnormal functioning of enzymes, cell proteins that regulate important chemical reactions in the body. Symptoms of metabolic disorders are usually present when the child is born or shortly afterward. Early diagnosis is important to prevent serious complications from developing.

Depending on your state's laws and your doctor's orders, your infant may be screened for the following disorders:

PKU

Around day two or three, some blood from your baby's heel will be tested for PKU(phenylketonuria). This disorder prevents the breakdown of certain amino acids found in the proteins of some foods. Infants born with PKU are normal at birth, but can be blonder and fairer than their siblings. Left untreated, PKU can lead to seizures and mental retardation. If PKU is identified, a special diet is necessary to prevent complications of the condition.

PKU is one of many conditions caused by an amino acid defect. Others include:

Maple syrup urine disease. An affected infant may have reflex changes, urine and perspiration odor that is sweet-smelling, convulsions; coma and death may also occur.

Histidinemia. Retardation may be present, but the condition is usually benign.

Homocystinuria. Infants with the condition may have skeletal abnormalities, retardation and blood clots.

Galactosemia

Galactose is a simple sugar formed during digestion of lactose, the principal sugar in milk. Babies with galactosemia (one in about 45,000) cannot metabolize galactose because of an enzyme deficiency, abnormal levels of galactose accumulate in the baby's blood. They have feeding difficulties, vomiting and weight loss, and this condition can lead to cataracts and brain or liver damage. A simple blood test can diagnose this rare disorder. It must be found early and the infant must be placed on a a galactose-free diet before the brain and liver are irreversibly damaged.

Hypothyroidism

Hypothyroidism is a deficiency of activity in the thyroid gland, an endocrine gland that regulates the body's functioning. When there is a lack of thyroid activity in a newborn,
the following conditions may occur:

• respiratory distress
• jaundice
• blue-tinged skin color
• poor feeding
• hoarse cry
• umbilical hernia
• slow bone growth

To diagnose the disease, umbilical cord blood or blood from the baby's heel is tested to look at thyroid levels. If there is a deficiency, treatment with thyroid hormones is begun immediately. If treatment is not begun promptly, mental retardation may result. The condition will be monitored until thyroid levels are normalized.

Screening may also be done for cystic fibrosis or for sickle cell anemia, an abnormality of the oxygen-carrying red blood cells that occurs primarily in African-Americans.

Last Updated: 10/10/2002
The Johns Hopkins University 1996-2003.  All rights reserved.  This information is not intended to provide advice on personal medical matters, nor is it intended to be a substitute for consultation.