Infant Thyroid Problems

Essential for normal brain development and growth, the human thyroid plays a large role in regulating hormones throughout the body. During pregnancy, a the thyroid of a fetus may not develop properly, and infant hypothyroidism is diagnosed. Though hypothyroidism may negatively affect development and brain growth, treatments exist to help infants diagnosed with hypothyroidism lead normal lives.

History

• The thyroid gland is located at the front of the neck and takes in the iodine consumed to turn it in to the thyroid hormone--thyroxine T4. The thyroid gland works with the pituitary gland to send necessary T4 hormones to the brain. In some babies, the thyroid isn't developed enough. The infant's levels of T4 may be off, and growth is affected. Most states require a newborn screening test to test for infant hypothyroidism.

Types

• The two types of infant hypothyroidism are permanent congenital hypothyroidism and transient congenital hypothyroidism. Permanent congenital hypothyroidism requires life-long treatment and is caused by a defect or abnormal growth in the thyroid gland. Transient congenital hypothyroidism occurs in 10 to 20 percent of cases, and it usually only lasts for the first one to three months of an infant's life. It can be caused by excessive exposure to iodine or exposure to anti-thyroid medication during pregnancy.

Identification

• Infants with hypothyroidism may appear sleepy all of the time and have trouble taking the breast or bottle. They may be constipated or have gas as well as poor growth patterns. At birth, they may experience jaundice longer than other infants. Also, they may be quieter than other babies and seldom cry. In addition to a general disinterest in their environment, these babies may feel floppy when picked up and have poor circulation.

Significance

• Infant hypothyroidism is the most common cause of mental retardation when not detected and treated early. Starting treatment early proves to be an effective way to prevent it, however. Even with treatment, though, mental retardation is difficult to predict, as there may not be enough T4 for adequate brain development. In addition, untreated infant hypothyroidism may result in dwarfism.

Treatment

• Treatment for infant hypothyroidism is relatively simple and consists of one dose per day of a synthetic hormone. Sometimes called sodium levothyroxine or L-thyroxine, these tablets act exactly like the hormone produced naturally by the thyroid. There are no side effects from the tablets when taken properly. An infant with a congenital thyroid problem will take the hormones for the rest of her life, and she will probably develop normally as long as the hormone treatment continues.