Endocrine Abstracts

Introduction: The basic characteristics of metabolism in pregnancy are changes from anabolic to catabolic conditions. During early gestation, the fetus is dependent on maternal thyroid hormones that cross the placenta. Thyroid disease in pregnancy is a common clinical problem, at least 2–3% of women have thyroid dysfunction. Pre-conceptual education and appropriate diagnosis and treatment of thyroid dysfunction in early pregnancy are of great importance, with the aim of preventing complications during pregnancy and offspring. In the first trimester, the ‘normal’ range for TSH is reduced to 0.1–2.5 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 parameters and variations of thyroid function during pregnancy.

Matherial and methods

This study included 77 healthy pregnant women in the first trimester of pregnancy registered in the Center for endocrinology of Clinical Center Kragujevac. Blood samples were collected for fT4, TSH and TPOAb and measured by RIA method.

Results: The mean age of 77 patients was 30.8 ± 4.7 years. The prevalence of autoimmune thyroid disease was 25.9% and positive family history for thyroid disorder was in 9%. When we excluded patients with disorders of glicoregulation, the average serum level for fT4 in first trimester was 10.68 ± 2.16 pg/ml, for TSH was 2.09 ± 1.11 mIU/l, the average serum level for fT4 in the second trimester was 7.58 ± 2.11 pg/ml, for TSH was 2.59 ± 1.47 mIU/l, and the average serum level for fT4 in the third trimester was 7.18 ± 1.48 pg/ml, for TSH was 2.48 ± 1.18 mIU/l. For the first time, we shown reference range for thyroid parameters in our population in trimesters:

Conclusion: It has been shown that as pregnancy progresses, the value of thyroid parameters decreases.

Keywords: thyroid function, pregnancy.