Objective: To assess the iodine nutritional status and the prevalence of goitre during pregnancy in a region of Hungary that appeared to be iodine sufficient in previous studies.
Design: A cross-sectional voluntary screening study was organized in which 313 pregnant women participated.
Methods: Urine iodine concentration and the volume of the thyroid gland were measured in every woman. In the presence of low urinary iodine concentrations, goitre, or both, thyroid function tests were performed.
Results: Iodine deficiency was found in 57.1% of the pregnant women, and was severe in 15.6%. The volume of the thyroid gland was enlarged in 19.2% of individuals. Nodular goitre was found in 17 women (5.4%). The frequency of goitre and the mean thyroid volume were increased in the group of iodine-deficient women. In the 89 cases of iodine deficiency or goitre, thyrotrophin concentrations were in the normal range; however, the free triiodothyronine:free throxine ratio was increased in 97% of them, indicating that the thyroid gland was in a stimulated state in these individuals.
Conclusions: Iodine deficiency with high prevalence of goitre was recognized among pregnant women in an area that previously appeared to be iodine sufficient. An unexpected mild iodine deficiency was also noted in the non-pregnant control group. Reassessment and continuous monitoring of iodine nutritional status is warranted even in populations that are apparently considered to be 'at no risk' of iodine deficiency, especially in pregnant women. Regular administration of iodine, starting at preconception or in early pregnancy and continuing during the period of nursing, is recommended in these regions.