Assessment of Maternal Health and Thyroid Activity by Determination of TSH, fT3 and fT4 in Pregnant Women Taking a Vitamin Supplement Containing Iodine

Abstract: Background: During pregnancy, important changes occur in maternal thyroid function. The thyrotropic activity of human chorionic gonadotropin (hCG) has been studied by many authors. This hormone has similarities to thyroidstimulating hormone (TSH). This has led to the supposition that hCG is indirectly involved in thyroid stimulation. In pregnancy, TSH is inhibited, with low levels of fT3 and fT4; in recent years, some authors have found a relationship between raised thyroid hormones and the onset of hyperemesis gravidarum. Thus, increasing or starting levothyroxine therapy is not indicated in the first trimester of pregnancy. Nutritional supplements may have an important role; in fact, iodine may encourage more physiological thyroid function and could affect the onset or absence of hyperemesis gravidarum. Materials and Methods: To identify the incidence of hyperemesis gravidarum in two groups of women treated with multivitamin supplementation with or without iodine, we analysed TSH, fT3 and fT4 levels and the severity of symptoms in pregnant women with nausea and vomiting. Results: TSH levels were significantly reduced in the group treated with iodine. fT3 and fT4 showed a significant decrease in the group treated with the multivitamin supplement containing iodine. Conclusions: Our results also show that the multivitamin supplement containing iodine was more effective in controlling the onset of hyperemesis gravidarum, improving TSH, fT3 and fT4 levels.