Urine Iodine Levels in Preeclamptic and Normal Pregnant Women

The aim of this study was to investigate the urine iodine concentration in women with severe preeclampsia and in healthy women in Erzurum, Turkey. Urine specimens were obtained from 40 severe preeclampsia and 18 healthy pregnant women. Urinary iodine levels were determined by the Foss method based on the Sandell–Kolthoff reaction. The urinary iodine level for women with severe preeclampsia was 4.25 ± 2.7 µg/dL, lower than 20.89 ± 6.4 µg/dL of urinary iodine for healthy pregnant women (p < 0.001). Blood magnesium concentration was found to be 1.63 ± 0.05 mg/dL for women with severe preeclampsia, which is lower than that of healthy pregnant women (1.87 ± 0.05 mg/dL; p < 0.001). There was a positive correlation between urinary iodine level and blood magnesium level in pregnant women with preeclampsia (Pearson correlation coefficient = 0.43; p < 0.01). However, there was no correlation between urinary iodine level and blood magnesium level in healthy pregnant women. There was no difference in thyroid hormone levels (T4, TSH, FT4) between women with severe preeclampsia and healthy pregnant women. However, there was a difference in T3 thyroid hormone levels between women with severe preeclampsia (1.86 ± 0.4 µg/dL) and healthy pregnant women (1.45 ± 0.3 µg/dL; p < 0.001). There was also a difference in FT3 between women with severe preeclampsia (2.77 ± 0.4 pg/mL) and healthy pregnant women (2.41 ± 0.5 µg/dL; p < 0.01). Urinary iodine excretion is currently the most convenient laboratory marker of iodine deficiency. The method is useful for the rapid and low-cost assessment of iodine deficiency. Our results suggested that urinary iodine concentration might be a useful marker for prediagnosing preeclamptic women. In addition, iodine supplementation may also be considered for preeclamptic therapy.