Congenital Hypothyroidism in Children

What is congenital hypothyroidism?

Congenital (kon-JEN-i-tl) hypothyroidism (hi-po-THI-roi-dizm) is a condition that is present at birth. This occurs when the thyroid gland makes too little or no thyroid hormone. The thyroid gland is a butterfly-shaped organ that can be found in the front part of your neck. The thyroid hormones are special chemicals that help control how your body works. This includes keeping a normal body temperature, heart rate, and growth. The thyroid hormones also control how the body uses the energy it needs. This in turn affects how the body gains or loses weight. In children, thyroid hormones play an important role in normal growth and development.

What causes congenital hypothyroidism?

The exact cause of congenital hypothyroidism is usually not known. Caregivers think that problems during the growth of the fetus (baby) may cause congenital hypothyroidism. These problems may lead to defects in body parts, such as being born without a thyroid. The following are other conditions that may cause or increase your child's risk of having congenital hypothyroidism:

Changes or problems with your child's genes. A gene is a little piece of information that tells the body what to do or what to make.

Family history of hypothyroidism or other thyroid problems.

Having too little or no iodine in the expectant mother's diet may cause congenital hypothyroidism. Iodine is an important mineral used by the thyroid gland to work correctly and make thyroid hormones.

The expectant mother has hypothyroidism or is taking thyroid medicines during her pregnancy.

Other birth defects, such as Pendred's syndrome or congenital disorders affecting the heart, brain, and eyes.

What are the signs and symptoms of congenital hypothyroidism?

Signs and symptoms of congenital hypothyroidism may be present shortly after birth or during infancy. Newborn babies may show no obvious signs and symptoms.

Early signs and symptoms:

During your child's first weeks of life, he may have a number of signs and symptoms.

Bulging abdomen (belly).

Decreased body temperature.

Larger than normal fontanelles (soft spots on the skull).

Poor feeding.

Swelling of the eyelids, hands, or feet.

Yellowing of the skin and whites of the eyes.

Later signs and symptoms:

At ages 1 to 6 months, your child's signs and symptoms may become worse and more obvious.

Darkened, mottled (blotched), or dry skin.

Decreased activity and more sleepy.

Large tongue, hoarse crying, or troubled breathing.

Not able to gain weight.

Problems moving his bowel, such as constipation (dry, hard stools).

Older children may be shorter than what is expected for their age and their teeth may erupt (appear) late.

How is congenital hypothyroidism diagnosed?

Your caregiver will ask you about your child's health. This may include information on what signs and symptoms he may have and when they started. You may also be asked about your past pregnancy or diseases. He may also ask what medicines you have taken, or are taking now. You may also be asked about your family's health.

Blood tests:

A newborn screening test is usually done during your child's first days of life. A sample of your child's blood is taken and sent to the lab. This helps your child's caregiver learn if your child is at risk of having hypothyroidism or other genetic disorders.

Other blood tests may also be done to learn how well your child's thyroid gland is working. These tests may tell your child's caregiver how low his thyroid hormone levels are in his blood. This information may also be used to see how well any treatments are working.

Thyroid scan:

This test shows caregivers how your child's thyroid is working. Radioactive dye may be put into your child's IV or given to him to drink. The working part of the thyroid gland absorbs (soaks up) the dye. Two to 48 hours later, caregivers put a machine called a gamma camera over his neck. The machine takes pictures showing the areas of his thyroid that absorbed the dye. This test should not be done in newborns.

Thyroid ultrasound:

This is a test that looks at the inside of your child's thyroid gland. Sound waves are used to show pictures of his thyroid gland on a TV-like screen.

X-ray:

This is a test that takes pictures of the inside of your child's body. Your child's caregiver may use it to look for any problems and see how his lungs and heart are doing. X-ray pictures can also check your child's bones. These may help his caregivers see if he has problems with his growth and development.

How is congenital hypothyroidism treated?

Treatment for hypothyroidism will depend on your child's health, age, and the level of his thyroid hormones. Thyroid hormone medicines are given to replace and raise the hormone levels back to normal. If treatment starts within two weeks of life, your child will have normal growth, development and brain function. If another disease or condition has caused his hypothyroidism, it will also be treated. Medicines may also be given to decrease the symptoms of hypothyroidism.

What problems can congenital hypothyroidism cause?

Hypothyroidism if not diagnosed early or left untreated, may cause cretinism. Cretinism is a condition that causes learning problems, poor growth and intelligence, or mental retardation. Your child may also develop myxedema which is a dangerous condition. This causes extra fluid and swelling in your child's legs, ankles, lungs, or around his heart. Your child's temperature may go very low, and his heart may beat very slowly. He may have seizures (convulsions), or go into a deep coma and die if he does not get medical care quickly.

Where can I find support and more information?

Having a child with congenital hypothyroidism may be hard for you and your family. You and those close to your child may feel angry, sad, or frightened. These feelings are normal. Talk to your child's caregivers, family, or friends about your feelings. You may also want to join a support group. This is a group of people who also have hypothyroidism or other thyroid problems. Contact the following for more information:

American Academy of Family Physicians
PO Box 11210
Shawnee Mission, KS 66207-1210
913-906-6000
1-800-274-2237
http://www.aafp.org

American Thyroid Association
6066 Leesburg Pike, Suite 550
Falls Church, VA 22041
703-998-8890
800-849-7643
www.thyroid.org