Study on the prevalence of thyroid diseases during pregnancy in excess and sufficient water iodine area in Jiangsu Province

Abstract

Objective To study the prevalence of thyroid disease in pregnant women living in both excess and sufficient water iodine area of in Jiangsu Province,and to establish an epidemiological database of thyroid disorders among pregnant women in different water iodine area in Jiangsu Province in order to guide our clinical practise.Methods Fengxian and Suining of Xuzhou were selected as excess and sufficient water iodine region.All the 439 pregnant women within the first trimester were enrolled in our study.The name,age,and previous history were recorded on questionnaire.The samples of fasting blood were obtained.Serum parameters such as free triiodothyronine ( FT3 ),free thyroxine ( FT4 ),total thyroxine ( TT4 ),thyrotropic stimulating hormone ( TSH ),and thyroid peroxidase (TPOAb) were measured by electrochemiluminescence assay.The data of the eligible 396 subjects were stored and analyzed by Epidata after excluding subjects with previous thyroid dysfuncion,renal disease,heart disease,and pregnancy-induced hypertension syndrome.Results Among the 396 subjects,197 women ( 49.7％ ) had thyroid disorders. The prevalence of hyperthyroidism, subclinical hyperthyroidism, hypothyroidism, subclinical hypothyroidism,hypothyroxinaemia,and thyroid autoimmunity were 0.5％,6.3％,3.3％,29.3％,9.3％,and 1.0％,respectively.The prevalence of subclinical hypothyroidism was significantly higher in excess water iodine region (32.4％) than that in sufficient water iodine area ( 19.6％ ),while the prevalence of other types of thyroid diseases such as subclinical hyperthyroidism,hyperthyroidism,hypothyroidism,hypothyroxinaemia,and TPOAbpositive cases in either excess or sufficient water iodine regions was not different.Conclusions Subclinical hyperthyridism,hypothyroxinaemia,and subclinical hypothyroidism are the main thyroid disorders in pregnant women in both excess and sufficient water iodine area.The prevalence of subclinical hypothyroidism increases obviously in excess water iodine region,indicating the relationship between thyroid disease and high iodine intake. Key words: Pregnancy; Thyroid diseases; Prevalence; Excess iodine region; Sufficient iodine region