Thyroid hormones in pregnant women are of great importance in the process of forming a healthy child. Their effect extends literally to all organs and tissues of the mother’s body and the embryo. Therefore, timely registration of a pregnant woman with a gynecologist, observation of the period of gestation by narrow-minded doctors and the appointment of adequate drug therapy, if necessary, are important.

Functions of the thyroid gland in the body

The organ of internal secretion (thyroid), whose function is the synthesis of the body’s hormonal background, plays a huge role. Thyroid hormones in a pregnant woman are recognized as one of the main regulators of vital body processes, as they are involved in the intrauterine development of the embryo.

The function of the thyroid gland with indicators of hormones produced by it within the normal range is manifested in the following::

• adequate regulation of homeostasis, metabolic processes in the tissue structures of all organs and systems;
• promoting the formation of new cells with their structural differentiation and genetically programmed death of old cells;
• participation in the maintenance of normal body temperature, regulation of oxidation processes and energy production, oxygen consumption;
• control of neural regulation;
• promoting the neutralization of free radicals;
• influence on the mental, physical and mental development of the body;
• responsibility for the development of the immune system.

It is important to take into account that the formation of the fetal thyroid gland, which itself is able to accumulate iodine and synthesize hormones, occurs during pregnancy at 16-17 weeks. Until then, the embryo, the formation of its organs and systems directly depend on the functionality of the mother’s thyroid gland. In this regard, endocrinologists often observe an increase in the size of the thyroid gland during pregnancy, which is associated with an increasing intensity of its activity.

Relevance of early registration of a pregnant woman

Doctors ‘ recommendations about the need for early registration of a pregnant woman in a women’s clinic are justified. Even in the period of laying fetal organs (up to 12 weeks), the expectant mother is offered to undergo a full diagnosis of the body, including laboratory examination (hemogram, general urinalysis, blood biochemistry, blood test for thyroid hormones), functional tests (ECG, ultrasound), consultations of specialists of a narrow focus, including an endocrinologist. The fastest and most informative method for determining thyroid activity is laboratory monitoring of the levels of T3 (T3 total and T3 free) and T4 (T4 total and T4 free) hormones, thyrotropic hormone (TSH), antibodies to thyroglobulin (AT TSH) and therioid perioxidase (AT TPO). There are reference values for laboratory diagnostics that signal the development of thyroid disease if they do not meet the standards.

The norm during pregnancy, that is, compliance with the above indicators of laboratory diagnostics, does not require medical correction, with the exception of the use of iodine preparations prescribed by an endocrinologist for preventive purposes, which should be used throughout the entire period of carrying a child.

It is important to take into account that, despite the thyroid gland formed in the fetus at the time of 16-17 weeks of pregnancy, the only source of iodine for it is iodine circulating in the mother’s bloodstream. Daily requirement for iodine during pregnancy, this requirement increases to 200 mcg per day, which is not achieved with food intake, therefore, it is corrected by the appointment of iodine preparations by an endocrinologist. If there is a lack of iodine in a pregnant woman, there are signs of a decrease in the function of the thyroid gland (hypothyroidism), which negatively affects the development of the fetus, threatens spontaneous miscarriage.

Analysis of a laboratory study of thyroid function during pregnancy

Comparison of the reference values of laboratory diagnostics of the thyroid hormone background with real values suggests the presence of abnormalities in thyroid activity. However, for the conclusion of the diagnosis, the total value of several indicators is important. Considering all the values in a complex, it is possible to conclude with 100% probability the development of a pathological process and prescribe adequate treatment for a pregnant woman without threatening the development of the fetus.

In particular, if the thyroid-stimulating hormone that stimulates the secretion of T3 and T4, as well as the level of thyroxine 4 total are lowered, and antibodies to thyroperoxidase are increased during pregnancy, then we can judge the development of hypothyroidism, characterized by insufficient thyroid function.

On the contrary, hyperthyroidism is accompanied by an increase in the level of T4 total, T4 free.

Pregnancy, iodine deficiency goiter, thyrotoxicosis are manifested in an increase in the level of triiodothyronine (T3 total). Lowered T3 total-evidence of impaired metabolic functions, hypothyroidism. Thyroxine free 3 looks for differential diagnosis, it is paired with T3 and confirms or excludes thyroid disease.

The signal of structural disorders of the thyroid gland is a high thyroglobulin (TG) index.

Useful diagnostic test for AT TPO to detect goiter atrophic thyroiditis, primary thyrotoxicosis, Hashimoto’s goiter. The presence in the blood of overestimated numbers of antibodies to TPO diagnoses the listed thyroid diseases and requires differential diagnosis, namely ultrasound of the thyroid gland.

Autoimmune diseases of the thyroid gland can be detected if the titer of antibodies to thyroglobulin (AT TG) is increased.

It is important to know that for the reliability of a laboratory examination, you need to exclude the following one month before taking the tests::

• taking medication replacement therapy (thyroid hormones);
• sports activities;
• psychoemotional load.