正常孕妇早中晚孕期的甲状腺激素参考值范围

目的 建立正常孕妇早、中、晚孕期的甲状腺激素参考值范围,为诊断、治疗、监测(或筛查)孕妇甲状腺疾病以及相关研究提供参考.方法 在碘营养充足地区一次性横断面调查孕妇及非妊娠妇女,通过统一设计的调查表和实验室检测结果严格筛选出505名不同孕期的正常孕妇和153名正常非妊娠妇女(作为对照),建立甲状腺激素参考值范围;甲状腺激素测定采用化学发光免疫测定方法,参考值范围采用中位数(P50)及双侧限值(P2.5和P97.5)表示.结果 进入本研究的所有妇女家庭均食用加碘盐,她们的尿碘中位数均达到了适宜水平,表明这些妇女不存在碘缺乏或碘过量.孕妇的TSH水平在孕早期明显低于非妊娠妇女(P<0.01),孕中期开始回升,但到孕晚期时仍未完全恢复到非妊娠水平;孕妇的FT4和FT3,随妊娠时间逐渐下降,孕中期和孕晚期均明显低于非妊娠妇女(P<0.01);孕妇的TT4和TT3自孕早期开始即明显升高(P<0.01),至孕中期达峰值,大约是非妊娠的1.5倍.结论 孕妇的甲状腺激素水平不同于非妊娠妇女,早、中、晚孕期之间也存在明显差异.因此,建立正常孕妇早、中、晚孕期的甲状腺激素参考值范围具有临床意义.

Trimester-specific reference data of thyroid hormones for normal pregnancy

Objective To set up the trimester-specific reference ranges of thyroid hormones for normal pregnant women to provide reference criteria for diagnosis, treatment and monitoring or screening of thyroid disease during pregnancy and related research. Methods A cross-sectional survey was conducted in pregnant and non-pregnant women in iodine sufficient areas. A total of 505 normal pregnant women and 153 normal non-pregnant women (as control) were selected for establishing trimester-specific reference ranges of thyroid hormones after rigorous screening through the survey questionnaire and laboratory tests. Thyroid hormones were measured by Bayer automated chemiluminescence immunoassay, and the reference range of each hormone was calculated as median (the 50th percentile value) and two-sided limits (the 2.5th and 97.5th percentile values). Results All women investigated were in iodine sufficient status within optimal urine iodine level. The serum TSH level during the 1st trimester was obviously declined compared with that in the non-pregnant individuals (P < 0.01), and started to rise during the 2nd trimester, but was still not restored to non-pregnant level until the 3rd trimester. Serum FT4 and FT3 levels gradually decreased from the 2nd trimester to the 3rd (P < 0.01), and the TT4 and TT3 levels were markedly elevated since early pregnancy (P < 0.01) and reached peak levels at the 2nd trimester approximately making up to 1.5 times of those in the non-pregnant individuals. Conclusion The thyroid hormone levels during pregnancy differ completely from those of the non-pregnant individuals, and also differ during different gestation periods. Therefore, to establish trimester-specific reference data of thyroid hormones during normal pregnancy may be important for clinical practice.