People who do not have a medical education, having heard the expression “congenital hypothyroidism”, may not fully understand the essence of this disease. By itself, such a pathological condition as a decrease in thyroid function (hypothyroidism) has long been known to medicine. He has many reasons. The pathogenesis has been studied. There are treatment regimens. Adding the word “congenital” to the diagnosis clearly indicates the time of onset of the disease in the patient. Immediately after birth. This significantly complicates the whole fight against this pathology. In fact, the first doctor who will encounter congenital hypothyroidism will not be a pediatric endocrinologist, but a neonatologist or a local pediatrician. It is up to them to put the correct diagnosis on the child.
Causes of the disease
In order to recognize congenital hypothyroidism and treat it later, it is not necessary to know its cause. After all, this term means hypothyroidism of any etiology, the manifestation of which occurs at birth. It is much more important to start adequate therapy as soon as possible. But the reasons are important in terms of predicting the disease and assessing the likelihood of a similar pathology in other children in the family.
These include:
- incomplete maturation of the thyroid gland;
- native damage to the synthesis of thyroid hormones (meaning present at birth);
- incomplete maturation of the hypothalamic-pituitary system;
- external influences (drugs, autoimmune intrauterine interactions between mother and child).
Not so long ago, scientists have identified specific gene mutations that can provoke congenital hypothyroidism. Such cases are rare. They are classified as a separate form of this pathology.
The mechanism of the development of the disease
While the child is in the womb, even if he has no or simply reduced thyroid function, no critical changes occur. This is due to the fact that the fetus receives thyroid hormones from the mother. This is enough for the brain to be developed by birth. However, the main period of maturation of the central nervous system occurs just after birth.
In congenital hypothyroidism, the level of thyroid hormones drops sharply during this period.
Because of this, the processes of formation of the sheath of nerve fibers throughout the body, of course, in the brain too, suffer significantly. As a result, this leads to the fact that the child will lag behind, first of all, in neuropsychic development. If the deficiency of hormones is prolonged, then physical development, bone mineralization and the formation of internal organs also slow down.
Signs of the disease
Manifestations of congenital hypothyroidism do not have, unfortunately, any specific features. Therefore, they do not help for timely diagnosis. Only in 5% of cases, symptoms in newborns allow us to suspect a lack of thyroid hormones. There are early and late manifestations.
Early signs of hypothyroidism in a newborn include:
- voice change (bass tone);
- big belly (due to bloating);
- umbilical hernia;
- decreased skeletal muscle tone;
- large posterior fontanelle;
- macroglosia ;
- hyperplasia of the thyroid gland;
- prolonged physiological jaundice (more than seven days).
In the differential diagnosis of these symptoms, many other congenital diseases must be excluded. Therefore, in order to recognize congenital hypothyroidism as quickly as possible, a screening test is performed on the 4-5th day of a child’s life. Previously, it cannot be done due to the high probability of a false positive result. This is all because after birth there is a physiological decline in hormones. Treatment of a disabled child is ten times more expensive than such a test.
It will be difficult for any parent to realize that the child could develop normally if treatment was started on time.
If replacement therapy is not started within 3-4 months, then the following symptoms appear in the baby:
- insufficient weight gain;
- dry skin;
- increased gas formation (flatulence);
- difficulty in swallowing;
- loss of appetite;
- decreased muscle tone;
- pale skin;
- the child’s tendency to constipation;
- low body temperature (hypothermia).
The appearance of these complaints is due to acute hormonal deficiency and indicates that the child may already have irreversible changes in the body from various organs and systems. By six months, with congenital hypothyroidism, a delay in the neuropsychic and physical development of the child develops. Plus, there are features such as:
- long closure of fontanelles;
- retraction of the bridge of the nose;
- disproportionate growth;
- hypertelorism (usually a large distance between the eyes).
Further lack of proper treatment only exacerbates the delay in the
psychomotor development of the child up to severe dementia and severe
infantilism.
There is a favorable variant of congenital deficiency of thyroid hormones. This
is transient hypothyroidism. In this case, the normal functioning of the
thyroid gland is restored over time, and treatment is not required.
Treatment of the disease
If there is a low level of TSH (thyroid stimulating hormone) in blood spots dried on filter paper or in its biochemical analysis by the end of the first week of a child’s life, then treatment should be started immediately. Its main goal is to bring the level of the T4 hormone to normal as quickly as possible. This will lead to the maintenance of T4 and TSH at the desired level and will enable the proper formation of the nervous system, skeleton and internal organs. Treatment usually begins with a daily starting dose of L-T4 10-15 mcg per kilogram of body weight. After control examinations, the dose is adjusted depending on their result. With age, the amount of thyroid hormone required also increases, and therefore the dose of L-T4 will also need to be gradually increased.