Iodine nutritional status and thyroid function of pregnant women during the third trimester of pregnancy in an iodine-sufficient area

Objective:To explore the iodine nutritional status and thyroid function of pregnant women during the third trimester of pregnancy in an iodine-sufficient area.Methods:The morning-urine and venous blood samples of 174 pregnant women during the third trimester of pregnancy were collected,arsenic-cerium catalytic spectrophotometer was used to detect the content of iodine in urine,chemiluminescence was used to detect the levels of free triiodothyronine(FT3),free thyroxine(FT4) and sensitive thyroid-stimulating hormone(sTSH);radioimmunoassay was used to detect thyroid peroxidase antibody(TPOAb) and thyroglobulin antibody(TGAb).Results:The average age of the pregnant women was(28.07±4.87) years.The median of urinary iodine was 217.06 μg/L,63.2% of the pregnant women had an appropriate iodine nutritional state,and partial pregnant women were found with iodine deficiency(27.6%) and iodine excess(9.2%).The positive rates of TPOAb and TGAb were 24.1% and 3.4%,respectively.4 pregnant women suffered from subclinical hypothyroidism,accounting for 2.3%.There was no correlation between urinary iodine and FT3,FT4 and sTSH levels(P0.05).There was no significant difference in positive rate of antibody among the pregnant women with different urinary iodine levels(P0.05).Compared with the pregnant women with negative TPOAb,the level of FT3 in pregnant women with positive TPOAb decreased,while the levels of sTSH and urinary iodine increased;compared with the pregnant women with negative TGAb,the level of sTSH in pregnant women with positive TGAb decreased(P0.05).Conclusion:The whole iodine status of pregnant women in this area is adequate,but there are still some individuals with iodine deficiency and iodine excess.Positive thyroid autoantibodies may lead to the disfunction of thyroid in pregnant women.As a result,the monitoring of urinary iodine level and thyroid function should be strengthened during pregnancy.