The study of test index in thyroid function of pregnant women

Objective This study attempts to explore the prevalence and changes of thyroid function of pregnant women and to put forward the suggestions as to the screening of thyroid function in pregnancy. Methods This study conducts a Cross-sectional study on 289 cases of pregnant women from the maternity clinic in the First Hospital Affiliated to Fujian Medical University,starting between September 2011 and September 2012. All the pregnant women were categorized into a normal pregnancy group of 372 cases( group A),and a thyroid disease high risk group of 40 cases( group B). A prevalence comparison is made between the high-risk group and the normal group through antenatal examination,through the antenatal examination,repectively of the pregnant women with positive thyroid peroxidase antibodies( TPOAb) and the ones with TPOAb negative. A correlation analysis is also made on the thyroid-stimulating hormone( TSH),TPOAb and serum free thyroxin( FT 4). On that basis,a calculation is conducted of the median serum FT 3,FT 4,TSH and reference range of serum FT 3,FT 4,TSH levels at early,mid and late pregnancy in the normal pregnancy group. Results 1. 103 cases in Group A are diagnosed as suffering thyroid diseases,respectively as follows: 19 of clinical hypothyroidism,32 of subclinical hypothyroidism,29 of low T 4 concentration,3 of clinical hyperthyroidism,and 20 of subclinical hyperthyroidism, which points to a prevalence of 27. 69%. In the meantime,30 cases in Group B were diagnosed as patients with thyroid diseases,including 6 cases of clinical hypothyroidism,9 cases of subclinical hypothyroidism and 5 of low T 4 concentration,3 of clinical hyperthyroidism,7 of subclinical hyperthyroidism,which points to a prevalence of 75%. 2.TSH levels have positive correlation with TPOAb while being negatively correlated to FT 4. Positive TPOAb is a risk factor for elevated TSH levels. And FT 4 level and duration of pregnancy is the protecting factor for elevated TSH levels. 3,In mid-term pregnancy,the prevalence of hypothyroidism among the pregnant women with positive TPOAb is higher than the ones with negative TPOAb and the discrepancy is statistically signicant. The difference in the TSH levels between the two is also statistically significant. 4. The values of FT 3,FT 4,and TSH during the whole pregnancy are lower than non-pregnancy periods. FT 3 and FT 4 showed a general declining tendency while TSH values descend to the bottom in the first trimester of pregnancy,rising at mid-period,and then slightly lowering towards the end of pregnancy. Conclusion The screening of pregnant women concerning their thyroid functioning has its rationality,for confining the screening to highrisk pregnant women will lead to a high rate of missed diagnosis among normal pregnant women. In order to make correct diagnosis of gestational thyroid disease,there is need to establish specific standards for thyroid gestational,screening that is suitable for local normal iodine intake level.