Öz
We aimed to investigate the thyroid function test (fT4 and TSH) results and the prevalence of hyperthyroidism, euthyroidism, subclinical hypothyroidism, and overt hypothyroidism according to age groups in pregnant women who had applied to our hospital. Six thousand eight hundred and fourty-three pregnant women who were in the first trimester and who applied to the hospital for the first time in their current pregnancy were included in the study. Patients were divided into 3 age groups, namely, ≤19 years, 20-34 years, and ≥35 years. The fT4 and TSH levels were compared between the age groups. The mean serum TSH value of patients was 1.61(0.987, 2.41) mIU/mL. There was no statistically significant difference in the rates of hyperthyroidism, euthyroidism, subclinical hypothyroidism and overt hypothyroidism between the three age groups. However, the incidence of hyperthyroidism in pregnant women aged 35 years and older was significantly higher when compared with those aged 35 years and younger. Consistently with the previous studies in our country, the prevalence of hyperthyroidism, subclinical hypothyroidism and overt hypothyroidism was detected as 2.9%, 22.1%, and 0.4%, respectively. Therefore, we recommend regular thyroid testing in pregnancy regardless of age, especially in countries where iodine deficiency is common.