ABSTRACT
OBJECTIVE: Thyroid nodules are a common finding in the general population. The primary aim of the study was to determine the prevalence of thyroid nodules and cancer found by ultrasound (US) in women who underwent screening for thyroid dysfunction during pregnancy. DESIGN: A double-centric, retrospective, cohort study. PATIENTS AND METHODS: We searched through medical records, including thyroid ultrasonography, of pregnant women who were positively screened for thyroid disorders (using thyroid-stimulating hormone and thyroid antibodies) from an unselected population ('universal screening group', n = 690) and of women who underwent the testing based on the presence of clinical risk factors defined by American Thyroid Association ('case-finding group', n = 249). RESULTS: Prevalence of benign and malignant thyroid nodules was lower in the 'universal screening group' than in the 'case-finding group' (9.9% vs 17.7%, P= 0.002, and 0.9% vs 7.2%, P< 0.001, respectively). Consistently, the thyroid cancer rate was lower among the nodules in the 'universal screening group' than in the 'case-finding group' (8.1% vs 29.0%, P= 0.003). Ultrasound EU-TIRADS (European Thyroid Imaging and Reporting Data System) category ≥4 had a 95.8% sensitivity for thyroid cancer. In palpable nodules, the prevalence of cancer was significantly higher than in the non-palpable ones (44.0% vs 2.2%, P < 0.001). In a multivariate regression analysis, thyroid nodules were associated with a history of infertility and parity. CONCLUSIONS: Compared to the data from cancer registries, universal screening allowed detecting thyroid cancer in pregnancy three to five times more frequently, but the cancer rate among nodules (8.1%) did not differ from the common population. US had very good sensitivity for thyroid cancer in pregnancy.
ABSTRACT
Iodine is an essential constituent of thyroid hormones. Thyroid hormones regulate brain development, growth and metabolism of the human body. Inadequately low iodine intake and decreased thyroid hormone synthesis can lead to iodine deficiency disorders. The severity of disorders depends not only on the degree of iodine deficiency, but also on the stage of the human development. Many areas of the world, including the Czech Republic, have been affected by natural iodine deficiency and the incidence of iodine deficiency disorders has been historically high. Fortification of food-grade salt was an effective step towards reduction of iodine deficiency impact. Although the Czech Republic has been considered to be an iodine sufficient area since 2004, iodine deficiency is still a threat to subgroups of population with an increased demand for iodine, such as pregnant women and newborns. Moreover, these groups are particularly sensitive to even mild iodine deficiency, because it could permanently affect the cognitive development of the fetus and have a negative effect on the course of pregnancy. Conversely, in other groups of the population steps taken to prevent iodine deficiency diseases may lead to excessive iodine intake with potential risks. It is necessary to control the iodine fortification and regularly monitor the iodine status of the population considering the individual risk groups.
