Iodine deficiency in pregnant women in an area of moderate goiter endemia.

Low levels of iodine, observed in endemic goiter areas, decrease the synthesis of T3 and T4. This phenomenon is particularly dangerous during pregnancy when demand for thyroid hormones increases considerably. Iodine deficiency may cause brain tissue damage of varying degree, even cretinism in most severe cases. The aim of the study was to make an initial evaluation of TSH and thyroid hormone levels, thyroid volume, and urine iodine excretion in pregnant women. The group under study consisted of 46 women, inhabitants of Kraków region. Their mean age was 26.8 years, 18 were primiparas and 28 multiparas. All deliveries were physiologica, vaginal, within the biological norm of 281 +/- 22 days from the last menstrual period. The concentrations of T3, T4 and TSH were determined in maternal and umbilical blood. Urine iodine levels were measured in the patients. Mean body weight of the newborns was 3338 g, mean pregnancy duration 39.6 weeks, and mean Apgar score 9.9. The results for maternal blood were (mean, SD in parentheses): T3 1.5 ng/ml (0.4), T4 11.6 micrograms% (2.9), TSH 2.3 microU/ml (1.2), thyroid volume 27.8 ml (15.2), urine iodine level 34.99 micrograms/l (29.12), and for umbilical blood T3 0.59 ng/ml (0.1), T4 10.6 micrograms/dl (2.1), FT3 1.28 pm/l (1.1), FT4 15.6 pm/l (4.8), TSH 3.7 microU/ml (0.9). Urine iodine level in pregnant women was several times lower than normal. 80% of the women under study had enlarged thyroid glands. We conclude that investigations of the problem should be continued.