妊娠期妇女甲状腺功能及相关指标参考区间的建立

Thyroid function in pregnant women and establishment of relevant indicators reference intervals

目的评估妊娠期妇女的甲状腺功能,建立本实验室妊娠期妇女的血清游离四碘甲状腺原氨酸(FT 4)、血清促甲状腺素(TSH)参考区间。方法选择妊娠前无甲状腺相关疾病及其他代谢疾病的5842例孕妇,检测血清FT 4、TSH水平,根据相关指南的标准分析其甲状腺功能情况。纳入TSH处在正常值范围的孕妇,比较不同时期孕妇的血清FT 4、TSH水平,并采用百分位数法估计妊娠期血清FT 4、TSH的参考值范围。结果3364例妊娠早期(T 1期)孕妇中,检出妊娠甲亢综合征54例(1.61%),亚临床甲减92例(2.73%);2310例妊娠中期(T 2)孕妇中,检出亚临床甲减57例(2.47%);168例妊娠晚期(T 3)孕妇中,检出亚临床甲减3例(1.79%)。按照FT 4水平低于参考值范围的第5、10百分位数,T 1期孕妇妊娠期低甲状腺素血症发生率分别为1.81%(61/3364)、9.36%(315/3364),T 2期孕妇分别为0、26.70%(617/2310),T 3期孕妇分别为3.57%(6/168)、8.93%(15/168)。T 1、T 2、T 3期孕妇TSH水平依次上升,而FT 4水平依次下降(均P<0.01)。T 1、T 2、T 3期孕妇FT 4的95%参考值范围分别为10.15~16.52 pmol/L、9.28~15.90 pmol/L、8.55~15.14 pmol/L,TSH的95%参考值范围分别为0.07~2.91 mIU/L、0.34~3.23 mIU/L、0.36~4.37 mIU/L。结论妊娠期女性存在一定比例的亚临床甲减及妊娠期低甲状腺素血症。由于实验方法及各地人群差异,建立本地区或实验室不同妊娠时期血清甲状腺功能指标参考值范围,有利于准确并及时诊断妊娠期妇女甲状腺功能异常。

Objective To evaluate the thyroid function of pregnant women,and to establish reference intervals of serum free tetraiodothyronine(FT 4)and serum thyroid-stimulating hormone(TSH)of pregnant women in our laboratory.Methods A total of 5842 pregnant women without thyroid related diseases or other metabolic diseases before pregnancy were selected,and received detection of serum FT4 and TSH levels,and their thyroid function was assessed according to the standard of related guidelines.The pregnant women with TSH within the normal range were enrolled,then serum FT 4 and TSH levels among pregnant women at different gestational periods were compared,and the reference ranges of serum FT 4 and TSH during pregnancy were evaluated by using the method of percentiles.Results Among 3364 pregnant women at early pregnancy(stage T 1),54(1.61%)cases were diagnosed as pregnancy-related hyperthyroidism syndrome and 92(2.73%)cases as subclinical hypothyroidism;among 2310 pregnant women at middle pregnancy(stage T 2),57(2.47%)cases were diagnosed as subclinical hypothyroidism;among 168 pregnant women at late pregnancy(stage T 3),3(1.79%)cases were diagnosed as subclinical hypothyroidism.According to FT 4 level below the 5th and the 10th percentile of reference ranges,the incidence rates of pregnant hypothyroxinemia were 1.81%(61/3364)and 9.36%(315/3364)in pregnant women at stage T 1,0 and 26.70%(617/2310)in pregnant women at stage T 2,and 3.57%(6/168)and 8.93%(15/168)in pregnant women at stage T 3,respectively.TSH level increased and FT 4 level decreased in pregnant women at stage T 1,stage T 2 and stage T 3 successively(all P<0.05).In pregnant women at stage T 1,stage T 2 and stage T 3,the 95%reference ranges of FT 4 were 10.15-16.52 pmol/L,9.28-15.90 pmol/L and 8.55-15.14 pmol/L,respectively,and the 95%reference ranges of TSH were 0.07-2.91 mIU/L,0.34-3.23 mIU/L and 0.36-4.37 mIU/L,respectively.Conclusion A certain proportion of subclinical hypothyroidism or pregnant hypothyroxinemia exists in pregnant women.As differences in the experimental method and population,establishing the reference ranges of serum thyroid function indices during different gestational periods for local region or laboratory is beneficial to accurate and timely diagnosis of abnormal thyroid function in pregnant women.