According to recent recommendations, thyroid tests in pregnancy should be performed only in women in risk groups. However, detailed studies indicate that such an approach results in missing hypothyroidism in 30% and hyperthyroidism in 69% of pregnant women. The aim of this study was to compare the effectiveness of diagnosing hypothyroidism in pregnant women by applying universal screening tests, and assessing risk factors. The study was carried out on 270 non-selected women in single pregnancy who underwent screening for hypothyroidism (diagnostic criteria: TSH > 2.5 mIU/L) during their first prenatal visit between the 6 th - 10 th week of gestation. After excluding the patients with pre-gestational hypothyroidism, risk factors for this disorder were assessed in the remaining subjects. A group of 28 patients (10.4% of all subjects) with hypothyroidism was selected for further thyroid tests, while the remaining 242 pregnant women (TSH < 2.5mIU/L) aged 26.3+/-3.59 formed the control group. Twenty subjects (71.4%) were thyroid antibodies-positive, while 8 patients were thyroid antibodies-negative. When analyzing hypothyroidism risk factors, one was found in 10 subjects (35.7%), 2 in 5 subjects (17.8%), whereas, in 13 subjects (46.4%) none were present. Symptoms suggesting thyroid dysfunction were discovered in 8 patients (53.3%), goiter in 5 patients (33.3%), another 5 patients (33.3%) had a positive gynaecological history, and only 2 patients had a positive family history of autoimmune thyroid diseases. During the analysis, it was found that TSH positively correlated with the age of the subjects. In the whole study group, a significant correlation was found between log TSH and hypothyroidism risk factors. Hypothyroidism (TSH > 2.5 mlU/L) was diagnosed in 10.4% of the patients. The primary cause of this pathology was thyroiditis which was diagnosed in 71.4% of the subjects. Hypothyroidism risk factors were present in 53.6% of the patients, while in 46.4% there were none, which indicates the necessity of carrying out screening tests in all pregnant women as a method of choice, regardless of the presence of thyroid disease risk factors. A positive correlation between the frequency of thyroid diseases risk factors, TSH, and the age of the patients in the presented study serves as an additional argument for the necessity of universal screening.