The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases (ChenyanL., Z.S., J.M., W.W., X.X., C.F., W.T.), Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Shenyang, 110001 China; Shenyang Women's and Children's Hospital (W.Z., ChenyangL.), Shenyang, 110011 China; Departments of Obstetrics and Gynecology (B.X.) and Endocrinology (S.Z.), No. 202 Hospital of People's Liberation Army, Shenyang, 110003 China; Dalian Obstetrics and Gynecology Hospital (L.B.), Dalian, 116003 China; Department of Obstetrics and Gynecology (T.M.), The First Hospital of China Medical University, Shenyang, 110001 China; Department of Endocrinology (J.D.), The First Affiliated Hospital of Dalian Medical University, Dalian, China; Department of Endocrinology (Z.G.), Dalian Municipal Central Hospital Affiliated of Dalian Medical University, Dalian, 116033 China; Department of Endocrinology (X.Z.), The First Hospital of Dandong, Dandong, 118000 China; and Shenyang Women and Children Health Care Center (L.Y.), Shenyang, 110032 China.
J Clin Endocrinol Metab. 2014 Jan;99(1):73-9. doi: 10.1210/jc.2013-1674. Epub 2013 Dec 20.
Guidelines of the American Thyroid Association (ATA) proposed that the upper limit of the TSH reference range should be 2.5 mIU/L in first trimester, but the reported ranges in China are significantly higher.
Our objective was to establish a rational reference range of serum TSH for diagnosis of subclinical hypothyroidism in the first trimester of pregnant women in China.
We screened 4800 pregnant women in the first trimester and 2000 women who planned to become pregnant and evaluated 535 pregnant women in follow-up visits during the second and third trimester.
Median concentrations of serum TSH decreased significantly from the seventh week of gestation. The median of TSH from 4 to 6 weeks was significantly higher than from 7 to 12 weeks (2.15 [0.56-5.31] mIU/L vs 1.47 [0.10-4.34] mIU/L, P<.001); however, there was no significant difference compared with nonpregnant women (2.07 [0.69-5.64] mIU/L; P=.784). The median of free T4 was not significantly altered in the first trimester. The prevalence of subclinical hypothyroidism in the 4800 pregnant women was 27.8% on the diagnostic criteria of TSH>2.5 mIU/L and 4.0% using the reference interval derived by our laboratory (0.14-4.87 mIU/L).Additionally, of 118 pregnant women who had serum TSH>2.5 mIU/L in the first trimester, only 30.0% and 20.3% of them at the 20th and 30th week of gestation had TSH>3.0 mIU/L.
The reference range for nonpregnant women can be used for the assessment of pregnant women at 4 to 6 weeks of gestation. The upper limit of serum TSH in the first trimester was much higher than 2.5 mIU/L in Chinese pregnant women.
美国甲状腺协会（ATA）指南建议，妊娠早期 TSH 的参考范围上限应为 2.5 mIU/L，但中国报道的范围明显更高。
本研究旨在为中国妊娠早期孕妇建立一个合理的血清 TSH 参考范围，用于诊断亚临床甲状腺功能减退症。
我们筛选了 4800 名妊娠早期孕妇和 2000 名计划怀孕的女性，并在妊娠中期和晚期的随访中评估了 535 名孕妇。
从妊娠第 7 周开始，血清 TSH 的中位数浓度显著下降。第 4-6 周的 TSH 中位数明显高于第 7-12 周（2.15[0.56-5.31]mIU/L 比 1.47[0.10-4.34]mIU/L，P<.001）；但与未怀孕的女性相比，差异无统计学意义（2.07[0.69-5.64]mIU/L；P=.784）。妊娠早期游离 T4 的中位数没有明显变化。4800 名孕妇根据 TSH>2.5 mIU/L 的诊断标准，亚临床甲状腺功能减退症的患病率为 27.8%，而根据本实验室（0.14-4.87 mIU/L）得出的参考区间，患病率为 4.0%。此外，在妊娠早期 TSH>2.5 mIU/L 的 118 名孕妇中，只有 30.0%和 20.3%在妊娠 20 周和 30 周时 TSH>3.0 mIU/L。
非妊娠女性的参考范围可用于评估妊娠 4-6 周的孕妇。中国孕妇妊娠早期血清 TSH 的上限远高于 2.5 mIU/L。
