Pregnancy is a physiological state in which significant changes in thyroid function occur. Several factors contribute to these changes. Indeed, since the beginning of pregnancy, the HCG (human chorionic gonadotrophin) secreted by the placenta, given its homology of structure with TSH (thyroid stimulating hormone), exerts a stimulatory effect on thyroid gland leading to an increase in the secretion of thyroid hormones (T3 and T4) and a decrease in TSH, especially during the first trimester. In addition, pregnancy induces increase in metabolic function and requires a higher production of thyroid hormone. Demand for iodine intake increases especially as there is a greater urinary excretion of iodine and a transfer of iodine to the fetus when his thyroid becomes functional. Early diagnosis and treatment of thyroid diseases before and during pregnancy is important for maintaining the health of the mother and the baby.

Thyroid, Pregnant Women.