成都地区妊娠妇女甲状腺激素正常参考值建立及甲状腺自身抗体对孕妇甲状腺功能的影响

Reference Intervals of Thyroid Hormones in Normal Pregnant Women and Effects of Thyroid Autoantibodies on Thyroid Hormone Levels in Pregnant Women in Chengdu Area

目的探讨成都地区妊娠期妇女甲状腺激素正常参考值范围、妊娠妇女甲状腺自身抗体阳性比率及甲状腺自身抗体对孕妇甲状腺功能的影响。方法随机抽取2013年6月至2014年3月间在成都市妇女儿童中心医院产科门诊进行妊娠常规检测的妊娠妇女696例,分别进行问卷调查、体格检查、甲状腺彩超和血清甲状腺激素水平测定。妊娠期正常参考值范围依据百分位数法确定,为同孕期健康妊娠妇女各指标的第2.5百分位数到第97.5百分位数范围(P2.5~P97.5)。同时纳入非妊娠妇女50例作为对照。结果在696例孕妇中,甲状腺自身抗体阴性579例,甲状腺自身抗体阳性117例,抗体阳性者占16.81%。579例甲状腺自身抗体阴性的孕妇中包括T1期(孕1~12周)257例、T2期(孕13~27周)202例、T3期(孕28~40周)120例。T1、T2、T3期的促甲状腺激素(TSH)正常参考值范围分别为:0.02~4.03mIU/L、0.02~4.05mIU/L、0.24~5.41mIU/L;游离甲状腺素(FT4)正常参考值范围分别为11.93~21.04pmol/L、11.23~19.22pmol/L、11.10~17.00pmol/L;游离三碘甲腺原氨酸(FT3)正常参考范围分别为:3.85~6.27pmol/L、3.51~5.82pmol/L、3.18~4.97pmol/L。与非妊娠妇女相比,妊娠妇女无论甲状腺自身抗体是否阳性,随着孕周的增大,TSH中位数水平均逐渐增加,FT4和FT3的中位数水平均逐渐降低;但与甲状腺自身抗体阴性的孕妇相比,甲状腺自身抗体阳性的孕妇变化幅度更加明显。在甲状腺自身抗体阳性的孕妇中,临床甲状腺功能减退、亚临床甲状腺功能减退、亚临床甲状腺功能亢进的发病率分别为0.85%、15.38%、0.85%。结论妊娠期妇女甲状腺激素水平不同于非妊娠状态,建立妊娠期特异性甲状腺激素参考值范围非常有必要。对于甲状腺自身抗体阳性的孕妇,应在妊娠期全程监测甲状腺激素功能的变化。

Objective To establish the reference intervals of thyroid hormones in normal pregnant women in Chengdu area of China, and to investigate the effects of thyroid autoantibodies on thyroid function in pregnant women. Methods We included 696 pregnant women who had gestation data from June 2013 to March 2014 in Chengdu Women Children＇s Central Hospital. Every subject under went questionnaire survey, physical examination, thyroid ultrasound and measurement of thyroid hormone and thyroid autoantibodies. The normal reference intervals were established according to the percentiles （Pz. 5-P97.5 ） of the healthy pregnant women in the same trimester. Another 50 non-pregnant women were selected as the control group. Results Of the 696 pregnant women, 579 subjects had negative thyroid autoantibodies and 117 subjects had positive thyroid autoantibodies. The positive rate of thyroid autoantibodies was 16.81%. Of the 579 subjects with negative thyroid autoantibodies, 257 were in the first trimester, 202 in the second trimester and 120 in the third trimester. In the first trimester of normal pregnancy, the reference intervals of serum thyrotropin （TSH）, free triiodothyronine （FT3）and free thyroxine （FT4） were 0.02-4.03 mIU/L, 3.85-6.27 pmol/L and 11.93-21.04 pmol/L respectively. In the second trimester, the reference intervals of serum TSH, FT3 and FT4 were 0. 02-4. 05 mIU/L, 3. 51-5. 82 pmol/L and 11. 23- 19.22 pmol/L respectively. In the thirdtrimester, the reference intervals for serum TSH, FT3 and FT4 were0.24-5.41 mlU/L, 3.18-4.97 pmol/L and 11.10-17.00 pmol/L, respectively. When compared with non-pregnant women, the median TSH value was increasingly consisted with the progress of pregnancy period, while the median FT4 and FT3 values were decreasing accordingly. The similar tendencies of TSH, FT3, and FT4 were found in pregnant women with positive thyroid autoantibodies, but the trends were more remarkable when compared with those with negative thyroid autoantibodies. In pregnant women with positive thyroid autoantibodies, the incidences of clinical hypothyroidism, subclinical hypothyroidism and clinical hyperthyroidism were 0. 85%, 15. 38% and 0.85 %, respectively. Conclusion The thyroid hormone reference ranges of pregnant women is quite different from those of non-pregnant women. It is necessary to establish the reference intervals of thyroid hormones in normal pregnant women. Thyroid function of pregnant women with positive thyroid autoantibodies should be monitored during the pregnant period.