妊娠期甲状腺功能检测指标研究

The study of test index in thyroid function of pregnant women

目的了解妊娠妇女甲状腺功能状况,并对妊娠期甲状腺功能筛查提出建议。方法选择福建医科大学附属第一医院2011年9月至2012年9月产科门诊的412例孕妇进行横断面研究。入选孕妇分为正常妊娠组(A组)372例,甲状腺疾病高危组(B组)40例。对正常孕妇及有高危因素的孕妇甲状腺过氧化物酶抗体(TPOAb)阳性与阴性者的患病率进行比较,并进行促甲状腺激素(TSH)与TPOAb、血清游离甲状腺素(FT4)等的相关性分析,计算本资料正常妊娠人群妊娠早、中、晚期血清游离三碘甲状腺原氨酸(FT3)、FT4、TSH中位数及参考范围血清FT3、FT4、TSH水平。结果 (1)A、B两组共诊断出甲状腺疾病分别为103例、30例,具体为:临床甲减19例、6例,亚临床甲减32例、9例,低甲状腺素(T4)血症29例、5例,临床甲亢3例、3例,亚临床甲亢20例、7例。(2)TSH水平与TPOAb正相关,与FT4负相关。TPOAb阳性是TSH水平升高的危险因素。而FT4水平及妊娠时限是TSH水平升高的保护因素。(3)妊娠中期TPOAb阳性孕妇亚临床甲减的患病率高于TPOAb阴性孕妇,差异有统计学意义。TPOAb阳性者与TPOAb阴性者TSH水平比较差异有统计学意义。(4)妊娠各期血清FT3、FT4、TSH均较非妊娠期下降。FT3、FT4值总体呈现持续下降趋势,妊娠中晚期下降趋于平稳。TSH值在妊娠早期降至最低点,中期上升,晚期较中期略下降。结论对妊娠期妇女进行甲状腺功能筛查有其合理性,如果仅对高危孕妇筛查,一般孕妇漏诊率高。需建立适合本地正常碘摄入水平的妊娠期特异性甲状腺功能筛查标准,才能对妊娠甲状腺疾病做出正确的诊断。

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 preva- lence 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 （ FT4 ）. On that basis, a calculation is conducted of the median serum FT3 , FT4, TSH and reference range of serum FT3 , KF4, 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 T4 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 hypothy- roidism, 9 cases of subclinical hypothyroidism and 5 of low T4 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 FT4. Positive TPOAb is a risk factor for elevated TSH levels. And FT4 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 FT3 , FT4, and TSH during the whole pregnancy are lower than non-preg- nancy periods. FT3 and FT4 showed a general declining tendency while TSH values descend to the bottom in the first tri- mester 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 high- risk 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.