Background: The levels of maternal thyroid hormone concentrations increase from early pregnancy, with a mild increase in free hormones in the first trimester with a corresponding lowering of serum TSH. Thyroid autoantibodies are found in 515% of women during childbearing age, and chronic autoimmune thyroiditis is the main cause of hypothyroidism. Thyroid hormone contributes critically to normal fetal brain development. In the first trimester, the normal range is reduced to 0.12.5 mIU/l, and in the second and third trimester is 3.0 mIU/l.
Aim: The aim of this study is to analyse concentration of thyroid hormones and the presence of TPOAb.
Material and methods: This study included 77 healthy pregnant women in the first trimester of pregnancy registered in Center for endocrinology CC Kragujevac. Blood samples were collected for fT3, fT4, TSH and TPOAb and measured by RIA method.
Results: We studied 77 healthy pregnant women in the first trimester of pregnancy. The mean age of patients was 30.8±4.7 years. The prevalence of autoimmune thyroid disease was 25.9%, positive family history for thyroid disorder was in 9%, smoking in 23.4% patients. The average serum level in patients without autoimmune thyroid disease (n=46) for fT4 was 10.68±2.16 pg/ml, for fT3 was 2.67±0.49 pg/ml, and for TSH was 2.09±1.11 mIU/l, but 37% women had increased TSH level (more than 2.5 mIU/l).
Conclusion: Our study showed that most of women during of first trimester of pregnancy had concentrations of thyroid hormones in reference range.
Keywords: thyroid function, pregancy