Iodine deficiency as a cause of hypothyroidosis in pregnant women: diagnostics and preventive measures

Abstract

Pregnancy is a period of increased demands on all organs and systems of the mother’s body, including the thyroid gland (TG). The productivity of the thyroid gland increases by 30–50%. For continuous and sufficient synthesis of thyroid hormones (TG) requires optimal intake of dietary iodine. The need for a microelement increases significantly during pregnancy, due to increased activity of the thyroid gland. Iodine deficiency of mild or moderate degrees leads to insufficient synthesis of thyroid hormones, despite its compensatory increase. Hypothyroidism in women is one of the causes of infertility. Hypothyroidism in pregnant women significantly increases the risk of preterm birth. Iodine deficiency has a serious impact on the intrauterine development of the fetus, because iodine and thyroid hormones (TG) are actively involved in the development of the fetus, the formation of various organs and the development of the brain. In order to prevent the dangerous consequences of iodine deficiency in the Russian Federation, mass prevention is carried out in the form of the use of iodized salt. During the 1st trimester of pregnancy, each woman undergoes a laboratory test of the level of TSH, total T4 and total T3 as a screening in order to correct the hypofunction of the thyroid gland in  time. In pregnant women, especially in  the first trimester, iodine requirements increase by 50%, which requires not only the mandatory use of iodized salt, but also the appointment of pharmacological preparations of iodine with an accurate dosage. Preventive measures may not be enough, then replacement therapy with levothyroxine is used throughout the pregnancy.