What is congenital hypothyroidism? — Congenital hypothyroidism is a condition that causes the body to have too little thyroid hormone. Babies can be born with it. (The word "congenital" means a condition a person is born with.)
Normally, there is a gland in the neck called the thyroid gland. It makes thyroid hormone. This hormone controls how your body uses and stores energy (figure 1). "Hypothyroidism" is the term doctors and nurses use when a person's body does not make enough thyroid hormone. Another term for this is "underactive thyroid."
This article is about congenital hypothyroidism that happens when a baby's thyroid gland does not work properly for no obvious reason. The gland might be missing, smaller than normal, or in the wrong place. Sometimes this turns out to be related to a genetic problem.
There are other forms of congenital hypothyroidism, too. These forms can happen to babies born to mothers who do not get enough of a substance called "iodine" in their diet. It can also happen if a woman gets too much iodine or takes certain medicines during pregnancy. These types of congenital hypothyroidism usually go away on their own. The type of congenital hypothyroidism discussed in this article needs to be treated, or it can cause serious problems.
What are the symptoms of congenital hypothyroidism? — Most babies with this condition have no symptoms. If they do, the symptoms can include:
Being less active than other babies
Problems with eating
Constipation (not having enough bowel movements)
Unusual appearance – Such as a large tongue, bulging around the belly button, or large soft spots on the head
Muscles that are weaker than those of other babies
Being very cold
Jaundice – A condition that makes the skin or the white part of the eye turn yellow. But most jaundice in newborn babies is not caused by hypothyroidism.
If your baby has any of the symptoms listed above, talk to the baby's doctor or nurse. Congenital hypothyroidism can cause life-long learning problems if it is not treated.
Is there a test for congenital hypothyroidism? — Yes. Today, most newborn babies in the United States and many other countries have a blood test to check for congenital hypothyroidism. The test is done as part of the routine newborn screening tests.
If the results of this test are abnormal, doctors might do other tests. These include:
Ultrasound – This test uses sound waves to create a picture of the inside of the body.
Thyroid scan – For this test, the baby drinks a liquid or gets a shot with a small amount of a radioactive substance. Then a camera or scanner creates a picture of the thyroid gland.
How is congenital hypothyroidism treated? — Congenital hypothyroidism is treated by giving a thyroid hormone pill every day. The pill replaces the hormone your baby's body cannot make normally.
To give your baby the pill each day, crush the pill into powder or very small pieces, and mix it with breast milk, formula, or water. If you are not sure how to do this, ask the doctor or nurse for help.
Important instructions to follow:
Avoid soy formula or soy milk. If your baby cannot drink regular formula made from cow's milk, ask his or her doctor what to use instead.
Do not change the dose or give more medicine without asking the doctor. Giving too much thyroid hormone can cause heart problems and giving too little can cause learning problems.
Give the pill every day, at the same time and in the same way. Your baby's doctor will tell you when and how to give it.
Children with congenital hypothyroidism need regular checkups. They also need blood tests to check hormone levels. Ask the doctor or nurse how often to get checkups and tests, and go to the child's appointments on time. The child needs to see a doctor or nurse regularly to make sure he or she is getting the right amount of thyroid hormone. Not giving the right amount of thyroid hormone can cause serious life-long problems.
Some children grow out of congenital hypothyroidism. The doctor will do a blood test to check for this. But most children need to keep taking daily thyroid hormone for life.
Can congenital hypothyroidism be prevented? — Not when it happens without a clear cause or because of a genetic problem. But learning problems related to congenital hypothyroidism can be prevented by:
Checking to make sure the baby is tested for congenital hypothyroidism right after birth. This is done as part of the newborn screening tests in the United States and many other countries.
Giving thyroid hormone for as long as the doctor recommends. Many people with congenital hypothyroidism need to take thyroid hormone for life.
Making sure the child with congenital hypothyroidism gets regular checkups and blood tests to see if he or she is getting the right amount of thyroid hormone.
If you have hypothyroidism (underactive thyroid) and want to get pregnant, talk to your doctor, nurse, or midwife. He or she can measure your thyroid hormone levels with a blood test. Having normal thyroid hormone levels can help you have a healthy baby.
What will my child's life be like? — Most babies with congenital hypothyroidism live normal lives if the condition is found and treated soon after they are born.
Having the right amount of thyroid hormone is especially important in babies and young children. The thyroid hormone helps the brain develop. If a child's brain does not get enough thyroid hormone, he or she can have learning problems. This causes life-long problems with thinking, learning, and doing daily activities.
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This topic retrieved from UpToDate on: Mar 30, 2020.
Topic 17218 Version 4.0
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