The thyroid gland is an organ of the endocrine system responsible for the production of iodine-containing hormones. It has the shape of a butterfly and is located on the front of the neck. Thyroid hormones have a wide range of effects on the human body. These include:
- metabolism,
- physical and psycho-emotional development,
- the work of the cardiovascular system,
- maintaining natural body temperature.
Congenital hypothyroidism is a disease in which a baby is born with a deficiency of the thyroid hormone (T4) produced by the thyroid gland. This hormone plays an important role in the regulation of growth, brain development and metabolism (the rate of chemical reactions in the body). Congenital hypothyroidism in children is one of the most common endocrine disorders. Worldwide, approximately one in two thousand newborns is diagnosed with the disease each year.
Most babies born with hypothyroidism seem normal at birth, usually due to the mother’s thyroid hormones obtained in the womb. If the disease is diagnosed at an early stage, it is easily treated with daily oral medication. Therapy allows a child with congenital hypothyroidism to lead a healthy lifestyle, have a normal growth and develop like all ordinary children.
Varieties
Some forms of congenital hypothyroidism in children are temporary. The condition of the baby improves within a few days after birth. Other forms of the disease are persistent. They can be successfully controlled by continuous hormone replacement therapy. Damage from the lack of treatment for hypothyroidism is irreversible, even if therapy is started a little later.
Causes
In 75 percent of cases, the causes of congenital hypothyroidism are defects in the development of the thyroid gland of the newborn. Here are a few possible features:
- lack of body
- wrong location
- small size or underdevelopment.
In some cases, the thyroid gland can develop normally, but is not able to produce enough thyroxine due to the lack of certain enzymes.
The concepts of congenital hypothyroidism and genetics are closely related. If the parents or immediate relatives had a history of thyroid problems, then there is a risk of their appearance in the newborn. About 20 percent of cases of congenital hypothyroidism are due to genetics.
An important factor is the lack of iodine in the diet of the mother during pregnancy. Various medicines used during gestation can also affect the development of the baby’s thyroid gland.
Among other things, the cause of hypothyroidism may be damage to the pituitary gland. He is responsible for the production of thyroid-stimulating hormone that controls the thyroid gland.
Signs and Symptoms
Usually children with congenital hypothyroidism are born on time or a little later and look completely normal. The vast majority of them have no manifestations of thyroxine deficiency. This is partly due to the ingestion of maternal thyroid hormones through the placenta. Within a few weeks after birth, the clinical signs and symptoms of hypothyroidism become more apparent. The brain of the newborn is at risk of irreversible damage. Because of this danger, it is important to start treatment as soon as possible.
For the above reasons, each child who is born, conduct various examinations. One of them is neonatal screening. With its help, in many newborns, hypothyroidism can be detected even before the onset of symptoms. Screening is done 4-5 days after birth. Previously, such an examination is not carried out because of the risk of obtaining a false-positive result.
In other cases, when an insufficient amount of iodine was introduced into the woman’s body during pregnancy, the baby may have early signs of hypothyroidism after birth, such as:
- puffy face;
- swelling around the eyes;
- enlarged swollen tongue;
- swollen belly;
- constipation;
- jaundice (yellowing of the skin, eyes and mucous membranes) and increased bilirubin;
- hoarse scream;
- poor appetite;
- decreased sucking reflex;
- umbilical hernia (protrusion of the navel out);
- slow bone growth;
- large fontanel;
- pale dry skin;
- low activity level;
- increased drowsiness.
Diagnostics
All newborns undergo neonatal screening in the first few days. Testing is done by taking a few drops of blood from the baby’s heel. One test is to verify thyroid function. The main indicator for the diagnosis of congenital hypothyroidism is a low thyroxine level and an increased thyroid stimulating hormone (TSH) in the newborn's blood serum. TSH is formed in the pituitary gland and is the main stimulator of hormone production in the thyroid gland.
Diagnosis and treatment should not be based solely on the results of neonatal screening. All newborns with thyroid pathology need to conduct an additional blood test. This analysis is taken directly from the vein. As soon as the diagnosis is confirmed, treatment with hormonal drugs is immediately started.
Also, for additional diagnosis of congenital hypothyroidism, ultrasound and scintigraphy (radionuclide scanning) of the thyroid gland can be performed. These procedures allow you to evaluate the size, location of the organ, as well as identify structural changes.
Treatment methods
The main treatment for congenital hypothyroidism is to replace the missing thyroid hormone with medication. The dose of thyroxine is adjusted as the child grows and according to the results of blood tests.
Clinical recommendations for congenital hypothyroidism are that treatment should be started as early as possible and should last a lifetime. Untimely initiation of therapy can lead to mental retardation. This is due to damage to the brain and nervous system.
Some features of treatment
Substitution therapy is done with a medicine called Levothyroxine (L-thyroxine). This is a synthetic form of the hormone thyroxine. Nevertheless, its chemical structure is identical to that produced by the thyroid gland.
There are some features of the treatment of congenital hypothyroidism:
- The child should receive hormone replacement drugs daily.
- The tablets are crushed and dissolved in a small amount of the mixture, breast milk or any other liquid.
- Children with hypothyroidism should be registered with an endocrinologist and a neuropathologist. And also undergo periodic examinations to monitor and adjust treatment.
The dosage and frequency of taking the medicine should be determined only by the doctor. If used incorrectly, side effects may occur. With an excess of the prescribed hormone in a child, the following symptoms may be present:
- restlessness
- loose stools
- loss of appetite
- weight loss
- fast growth,
- rapid pulse,
- vomiting
- insomnia.
If the dosage of Levothyroxine is insufficient, the following symptoms appear:
- lethargy,
- drowsiness,
- weakness,
- constipation,
- puffiness,
- rapid weight gain
- growth retardation.
Soy formulas and iron-containing medicines can reduce the concentration of the hormone in the blood. In these cases, the specialist must adjust the dose taken.
Effects
If treatment is started in the first two weeks after the baby is born, serious health problems can be prevented, such as:
- developmental delay,
- mental retardation,
- poor growth
- hearing loss.
Delayed treatment or its absence sooner or later lead to the appearance of the following symptoms:
- gross, swollen facial features;
- trouble breathing
- low hoarse voice;
- delayed psychomotor and physical development;
- decreased appetite;
- poor weight and height gain;
- goiter (enlarged thyroid gland);
- anemia;
- slow heart rate;
- accumulation of fluid under the skin;
- hearing loss
- flatulence and constipation;
- late closure of fontanelles.
Children who are left without treatment, as a rule, become mentally retarded, have disproportionate growth and weight, hypertonicity and unsteady gait. Most have speech delays.
Accompanying illnesses
Children with congenital hypothyroidism have an increased risk of developing congenital malformations. The most common heart disease, pulmonary stenosis, defects of the atrial or interventricular septa.
Hormone control
An important part of treatment is monitoring the level of thyroid hormones in the blood. The attending physician should monitor these indicators to ensure timely adjustment of medications. Blood tests are usually done every three months until one year is reached, and then every two to four months up to three years. After three years of age, laboratory tests are carried out every six months to a year until the completion of the growth of the child.
Also, during regular visits to the doctor, an assessment will be made of the physical characteristics of the baby, psychoemotional development and general health.
Risk group
A child is at risk for congenital hypothyroidism if he has any of the following diseases:
- Chromosomal abnormalities such as Down Syndrome, Williams Syndrome or Turner Syndrome.
- Autoimmune disorders such as type 1 diabetes or celiac disease (gluten intolerance).
- Thyroid injury.
Forecast
Today, children born with congenital hypothyroidism do not have serious developmental and growth delays. But for this it is necessary to begin treatment as early as possible - within a few days after birth. Infants who have not been diagnosed or whose therapy has been prescribed much later have lower IQ and physical health problems.
In the past, thyroxine deficiency was not diagnosed at birth and was not treated with hormone replacement therapy. As a result, the effects of congenital hypothyroidism were irreversible. In children, there was a serious delay in psychoemotional and physical development.
Newborns with hypothyroidism with timely treatment with correctly selected medications with constant medical supervision will grow and develop normally, like all healthy children. For some babies, a deficiency of the thyroid hormone is a temporary disease, treatment will need to be carried out from a couple of months to several years.
In order to prevent the occurrence of hypothyroidism in a newborn, a pregnant woman should take iodine-containing drugs.
Thyroid hormone deficiency can also occur in young children, even if the results of the birth test were normal. If your child has signs and symptoms of hypothyroidism, you should immediately consult a doctor.
Finally
Thyroid hormones play an important role in the regulation of growth and weight, the development of the brain and nervous system. Hormone deficiency leads to hypothyroidism. In early childhood, the disease is a leading cause of intellectual disability throughout the world. The success of the treatment lies in the timely diagnosis and immediate use of hormone replacement therapy. Synthetic thyroxine is the safest medicine to treat thyroid hormone deficiency. The lack of drug treatment leads to the development of mental retardation.