The monitor of urinary iodine and thyroid function in pregnant women

Objective To investigate the urinary iodine level,thyroid function of pregnant women and the neonatal thyroid function during different periods of pregnancy and iodine nutrient condition.To analyze iodine nutrient condition of pregnant women and necessity of supplemental therapy.Methods A total of 18 528 urinary samples of pregnant women from 1997.7 to 2003.3 in our hospital were collected and measured for iodine concentration.We separated the samples to different groups according to iodine supplement and pregnant trimester;group A without iodine supplement,group B with iodine supplement;the first trimester as group 1,the second trimester as group 2 and the third trimester as group 3.Another 246 pregnant women at the same time were randomly selected,and mother and neonatal thyroid function were measured,including 81 cases of the first trimester pregnant without iodine supplement,86 of term pregnant without iodine supply,and 79 of term pregnant with iodine supplement.Results ① The median urinary iodine of all cases was 231 μg/L.The incidence of urinary iodine50 μg/L,100 μg/L,200 μg/L was 2.4%,13.9% and 43.4%,respectively.② The urinary iodine of non-iodine-supplement group was tending to rise as the pregnant weeks increased(162 μg/L for group 1,193 μg/L for group 2 and 260 μg/L for group 3).③ The urinary iodine level of iodine-supplement group was significantly higher than non-iodine supplement group in the same gestational period(377 μg/L vs.162 μg/L for group 1,286 μg/L vs.193 μg/L for group 2,382 μg/L vs.260 μg/L for group 3).④ The median thyroid function was in the normal range.But FT 3,FT 4,TSH and TM were significantly different between early pregnant women and term pregnant women(P=0.000).No significant difference was observed in term pregnant women regard less of supplemental of iodine. No significant difference of thyroid function in the newborn of term delivery was presented(P0.05).⑤ TSH value of neonatal cord blood was5 mU/l in 22.3%,5 mU/L in 77.7% and10 mU/L in 38.5%.Conclusions ① Pregnant women in our hospital present iodine-deficient in some degree.② The urinary iodine can reflect iodine level of the pregnant women,so measuring the urinary iodine can guide supplement therapy,especially for the low thyroid function hypothyreosis.③ Urinary iodine is suggested to be measured and be guidance for iodine supplement especially in early pregnant women who vomits severely.