中国汉族碘适量地区妊娠月份特异性TSH和T4的正常参考范围

目的 建立中国碘适量地区妊娠月份特异性血清甲状腺激素的正常参考范围.方法 经过严格筛选得到碘适量地区妊娠4～36周(4周≈1个月)妇女1 118名和非妊娠妇女120名,检测血清TSH、TT4、FT4、甲状腺过氧化物酶抗体(TPOAb)以及尿碘水平.结果 妊娠期间,血清TSH在妊娠4周升高,之后开始下降,妊娠12周最低,比非妊娠时降低了35%,随后呈上升趋势,在妊娠晚期则保持稳定,与非妊娠对照组相比,TSH中位数升高了29%;血清TT4在妊娠早期迅速升高,在妊娠16周达到最高值,较非妊娠时升高70%,之后轻微下降,妊娠晚期则保持平稳,较非妊娠时升高50%;在妊娠早期,血清FT4先轻微升高,妊娠4周最高,之后逐渐下降,在妊娠中期仍然呈下降趋势,而在妊娠晚期则没有明显的变化.结论 建立妊娠月份特异性的血清TSH、TT4和FT4正常参考范围对于早期诊断妊娠亚临床甲状腺功能减退症和低T4血症是必要的.

Gestational month-specific reference ranges for TSH and thyroxine in Han nationality women in iodine sufficient area of China

Objective To establish the gestational month-specific reference intervals for thyrotropin and thyroxine in Han nationality women in iodine sufficient area of China. Methods In iodine sufficient area of China, 120 non-pregnant women and 1 118 pregnant women at gestational ages from 4 to 36 week (4 weeks≈1 month) were collected according to the strict criteria. Urinary iodine excretion and serum thyrotropin (TSH), total thyroxine (TT4), free thyroxine (FT4), thyroid peroxidase antibody (TPOAb) levels were determined in all subjects. Results During pregnancy, serum TSH increased at week 4, and then began to decrease with the lowest level at week 12, which was 35% lower than the non-pregnant level." After that, serum TSH increased gradually and finally became stable during the third-trimester of pregnancy (T3) when the level was 29% higher than that of non-pregnant controls. Serum TT4 elevated dramatically during the first-trimester with peak at week 16, which increased by 70% compared with the non-pregnant level, then slightly decreased, and became steady with 50% increasing compared with non-pregnant level. Serum FT4 initially increased slightly with peak at week 4, and then decreased gradually until the beginning of T3 without obvious fluctuation during T3. Conclusion The gestational month-specific reference intervals for TSH, TT4 and FT4 are necessary for the early diagnosis of maternal subclinical hypothyroidism and hypothyroxinaemia.