Urinary iodine as an important indicator for preeclampsia: a Polish perspective

Abstract Preeclampsia (PE) is one of the leading causes of perinatal and maternal morbidity. Although subclinical hypothyroidism in pregnancy is one of the established risk factors for PE, the link between iodine deficiency and PE is not fully understood. The aim of our study was to assess urinary iodine concentration (UIC), serum thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4) levels in Polish women with PE (PE group, n=78) compared with healthy non-pregnant women (CNP group, n=30), and healthy pregnant women (CP group, n=46). The UIC was determined by inductively coupled plasma mass spectrometry (ICP-MS). Both the mean UIC of 144.6±36.4 μg/L in the CP group and the mean of 125.8±33.6 μg/L in the PE group, respectively, were lower compared to non-pregnant women (149.8±28.8 μg/L), and the difference between the PE and CNP groups was statistically significant. TSH values were the highest in the PE group, while the lowest average level was for the CNP group. The fT3 and fT4 values in the PE group were significantly lower compared to the CNP and CP groups. Despite iodine supplementation during pregnancy, the UIC was lower compared to non-pregnant women, while in women with PE it was at a significantly lower level. To reduce the incidence of possible health complications, proper iodine supplementation and monitoring of the UIC is recommended for pregnant women suffering from PE or at risk of developing PE.