[Thyroid gland function during pregnancy]

In order to examine the thyroid gland function we analysed healthy pregnant women (20) with normal pregnancy course and term delivery, who had normal endocrinological findings before the investigated pregnancy. In all patients TSH, T4 and T3 concentrations were radioimmunologically determined by trimester, median values with standard deviations were analysed in order to establish normal values during gravidity, as well as the possible changes in relation to non-gravid condition. We determined that T4 (29.3%) and T3 (23.5%) concentrations significantly increased and that TSH insignificantly decreased (12.1%) in the first trimester of pregnancy. In healthy pregnant women during the advance of gestation there was a significant increase of T4 and T3, which was significantly higher in the following than in the previous trimester. TSH concentrations during pregnancy gradually decreased but the decrease during the whole course of pregnancy, and in separate trimesters, was not found to be statistically significant.