When a baby is born with an underactive thyroid, it is called congenital hypothyroidism . This condition causes the thyroid gland to not produce enough thyroid hormone, which eventually leads to health problems.
If detected and treated early, congenital hypothyroidism will not hinder the growth and development of your little one. But if left untreated, it can cause physical and developmental delays and irregular body functions.
Therefore, pay attention to the following information about what congenital hypothyroidism is, its symptoms, causes, and how to prevent it.
What is Congenital Hypothyroidism?
Quoting from MedlinePlus , congenital hypothyroidism is the partial or complete loss of thyroid gland function (hypothyroidism) that affects babies from birth (congenital).
The thyroid gland is a butterfly-shaped tissue in the lower neck. It makes hormones containing iodine, which play a role in regulating growth, brain development, and the rate of chemical reactions in the body (metabolism). People with congenital hypothyroidism have lower than normal levels of these hormones.
Congenital hypothyroidism occurs when the thyroid gland fails to develop or function properly. In 80 to 85 percent of cases, the thyroid gland is either absent, very small (hypoplastic), or abnormally located. These cases are classified as thyroid dysgenesis.
In other cases, the thyroid gland is normal in size or enlarged (goiter), but thyroid hormone production is decreased or absent. Most of these cases occur when one of several steps in the process of hormone synthesis is disrupted; these cases are classified as thyroid dyshormonogenesis.
Congenital hypothyroidism can also occur as part of a syndrome that affects other organs and tissues in the body. These forms of the condition are described as syndromes. Some common forms of syndromic hypothyroidism include Pendred syndrome, Bamforth-Lazarus syndrome, and brain-lung-thyroid syndrome.
Symptom
Babies with this condition may not show any signs or symptoms, although some babies with congenital hypothyroidism become less active and sleep more than usual. They may have difficulty feeding and may experience constipation .
If left untreated, congenital hypothyroidism can cause intellectual disability and slow growth. In the United States and many other countries, all hospitals test newborns for congenital hypothyroidism. If treatment is started within the first two weeks after birth, the baby will usually develop normally.
Other children may show some of the following symptoms at birth or acquire them during the first few months of their life:
- The navel protrudes too far (umbilical hernia)
- A hoarse sounding cry
- Large soft spot on the top of the baby’s head
- Big tongue
- Swollen face
- Constipation
- Difficulty feeding/breastfeeding
- Dry skin
- Muscle weakness
- Poor appetite
- Decreased energy levels
- Slow bone growth
- Yellow skin and eyes (jaundice)
- Mental retardation
- Very little crying
- Oversleeping
- Floppiness, low muscle tone
- Hoarse voice
- Pale skin
- Swelling of the skin (myxedema)
- Swelling in the neck due to enlargement of the thyroid gland (goiter)
Symptoms of congenital hypothyroidism can vary depending on the child, so screening is important to catch the condition early.
Reason
Some of the most common causes of congenital hypothyroidism are:
- Abnormal location of the gland (ectopic thyroid gland) : If the thyroid gland is located in an abnormal location in the neck, it usually will not function as it should.
- Underdeveloped thyroid gland (thyroid hypoplasia) : Sometimes, a child’s thyroid doesn’t form properly during their mother’s pregnancy. When the baby is born, they may have a small or partially developed thyroid.
- Missing thyroid gland (thyroid agenesis) : In other cases, a child may be born without a thyroid gland.
Medical experts aren’t entirely sure what causes this problem, but sometimes the condition is genetic.
In less common cases, a mother may take certain medications during pregnancy that can cause congenital hypothyroidism. Or, if the mother gets very high doses of iodine from her diet or supplements, it can cause congenital hypothyroidism in the child at birth.
Frequency of Occurrence
One child in every 2000-3000 is born with congenital hypothyroidism in the UK. Dysgenesis is more common in girls than boys but in dyshormonogenesis boys and girls can be affected equally.
Risk Factors
A child is at risk for congenital hypothyroidism if he or she has any of the following:
- Chromosomal abnormalities such as Down syndrome, Williams syndrome , or Turner syndrome
- Autoimmune disorders such as type 1 diabetes or celiac disease. These are diseases that involve some hormone deficiencies such as pseudohypoparathyroidism.
- Injury to the thyroid gland
- Certain hereditary genetic conditions
Babies who are born prematurely and whose thyroids are not fully developed are also at risk for congenital hypothyroidism.
Diagnosis
All newborns are screened for thyroid problems soon after birth. This test involves a few drops of blood taken from the baby’s heel and allows the doctor to identify the level of hormone production from the thyroid.
If the doctor deems it necessary, they may also use a CT scan or ultrasound to get a better look at the baby’s thyroid gland.
A heel prick blood sample is tested to look for:
- Low levels of T4 (thyroxine), a hormone made by the thyroid that helps control metabolism and growth.
- High levels of TSH (thyroid stimulating hormone), made by the pituitary gland to stimulate the thyroid and increase thyroid hormone production.
Babies born prematurely may need to be retested for thyroid problems a few weeks after birth. Repeating the standard newborn screening test will make sure their thyroid is developing as it should.
Treatment
Most often, you can treat your little one’s congenital hypothyroidism by giving them synthetic thyroid hormone every day. This type of treatment is called thyroid hormone replacement therapy and will help restore their thyroid hormone levels.
One of these drugs is calledlevothyroxine, which mimics the T4 (a type of thyroid hormone) that the body produces. It comes in tablet form, so depending on your child’s age, you may need to crush the tablet and mix it with a small amount of breast milk, water, or non-soy infant formula.
Giving your little one daily medication is essential to ensure that their blood levels are stable. Your doctor will monitor their blood thyroid hormone levels and adjust the medication as needed as they grow.
Doctors usually recommend testing a child’s blood once a month or every other month until they are 6 months old. After that, blood tests are usually done every 2 to 3 months.
Are There Any Side Effects of Treatment?
Treatment with levothyroxine simply replaces the thyroxine that the thyroid gland is unable to make. Therefore, treatment is to restore what the thyroid is not producing enough of. It is very effective and usually quite easy to give the correct dose.
If too much levothyroxine is given it can cause symptoms of an overactive thyroid (hyperthyroidism) such as restlessness, mild diarrhea, poor weight gain, poor sleep and rapid growth.
Too little levothyroxine can cause symptoms of an underactive thyroid (hypothyroidism) such as lethargy, constipation, cold extremities, or unexpected weight gain and slow growth.
Excessive treatment periods or prolonged treatment should not occur if blood tests are carried out regularly and parents attend regular reviews of their little one’s progress.
Possible Complications
Congenital hypothyroidism can affect a child’s normal growth and development. This includes sexual development. If left untreated, the condition can also cause:
- Low levels of red blood cells in the blood (anemia)
- Low body temperature
- Heart failure
Prevention
Congenital hypothyroidism is usually seen in developing countries where iodine deficiency is common.
Adults can prevent iodine deficiency by getting the Institute of Medicine’s recommended dietary allowance (RDA) of 150 micrograms of iodine per day. One teaspoon of iodized salt contains about 400 micrograms of iodine.
Because iodine deficiency in pregnancy can be harmful to the growing baby, pregnant women are advised to get 220 micrograms of iodine daily.
The American Thyroid Association recommends that all women who are pregnant or breastfeeding take a prenatal vitamin containing at least 150 micrograms of iodine daily.
That is the information about congenital hypothyroidism, hopefully it is useful for parents !
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Republished with permission from theAsianParent Indonesia
