Congenital hypothyroidism is a pediatric condition in which the thyroid gland is unable to produce adequate amounts of thyroid hormones, such as T3 and T4, which can compromise the child’s development and cause permanent neurological changes if not properly identified and treated.
The diagnosis of congenital hypothyroidism is made in the maternity ward using a heel prick test and, if hypothyroidism is confirmed, a specific dosage of thyroid hormones may be indicated.
The treatment of congenital hypothyroidism is carried out as soon as the diagnosis is confirmed, and the doctor recommends hormone replacement therapy to avoid complications for the baby. Congenital hypothyroidism has no cure, but when diagnosed and treated early, the child can develop normally.
Symptoms of congenital hypothyroidism
The main symptoms of congenital hypothyroidism are:
- Muscle flaccidity;
- Increased volume of the tongue;
- Compromised bone development;
- Difficulty breathing;
- Slower heartbeat;
- Anemia;
- Excessive drowsiness;
- Difficulty eating;
- Dry, inelastic skin;
- Delay in neuronal and psychomotor development.
Although there are symptoms, only around 10% of babies who suffer from congenital hypothyroidism present them, this is because the diagnosis is made in the maternity ward and hormone replacement treatment is started immediately afterwards, preventing the symptoms from appearing.
How the diagnosis is made
The diagnosis of congenital hypothyroidism is made during maternity during neonatal screening exams, normally through the heel prick test, in which a few drops of blood are collected from the baby’s heel and sent to the laboratory so they can be analyzed. See more about the heel prick test.
If the heel prick test indicates congenital hypothyroidism, T4 and TSH hormones must be measured through a blood test so that the diagnosis can be confirmed and treatment can be started. Other imaging tests, such as ultrasound, magnetic resonance imaging and thyroid scintigraphy, can also be used in the diagnosis. Find out more about the tests that evaluate the thyroid.
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Main causes
Congenital hypothyroidism can be caused by several situations, the main ones being:
- Non-formation or incomplete formation of the thyroid gland;
- Formation in an irregular location of the thyroid gland;
- Defects in the synthesis of thyroid hormones;
- Injuries to the pituitary gland or hypothalamus, which are two glands in the brain responsible for producing and regulating hormones.
Generally, congenital hypothyroidism is permanent, however, transient congenital hypothyroidism may occur, which may be caused by insufficient or excess iodine in the mother or newborn or by passage through the placenta of antithyroid medications.
Transient congenital hypothyroidism also requires treatment, but it is normally suspended at 3 years of age, so that tests can be carried out to assess the levels of circulating thyroid hormones and so that the type and cause of the disease can be better defined.
Treatment for congenital hypothyroidism
Treatment for congenital hypothyroidism consists of replacing thyroid hormones throughout life through the oral administration of a medicine, Levothyroxine sodium, which can be dissolved in a small amount of water or baby’s milk. When diagnosis and treatment are made late, the consequences of congenital hypothyroidism, such as mental retardation and growth retardation, may occur.
It is important that the child has their total and free T4 and TSH levels monitored so that the pediatrician can check the response to treatment.
