Gilbert Rhonda M, Hadlow Narelle C, Walsh John P, Fletcher Stephen J, Brown Suzanne J, Stuckey Bronwyn G, Lim Ee Mun
Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, and School of Medicine and Pharmacology, University of Western Australia, Perth, WA, Australia.
Med J Aust. 2008 Sep 1;189(5):250-3. doi: 10.5694/j.1326-5377.2008.tb02015.x.
To establish first-trimester-specific reference intervals for thyroid function tests in pregnant Australian women.
DESIGN, SETTING AND PARTICIPANTS: Serum samples were collected from 2159 pregnant women (9-13 weeks' gestation) attending a private pathology practice for first-trimester screening during October and November 2006. Levels of serum thyrotropin (TSH), free thyroxine (fT4), free triiodothyronine (fT3), thyroid peroxidase antibodies (TPOAb), and thyroglobulin antibodies (TgAb) were measured by chemiluminescent immunoassay (Abbott ARCHITECT analyser).
Reference intervals based on 2.5th and 97.5th percentiles for TSH, fT4 and fT3, after exclusion of 338 women with positive TPOAb or TgAb tests; comparison with reference intervals for non-pregnant women (TSH, 0.40-4.0 mU/L; fT4, 9-19 pmol/L; fT3, 3.0-5.5 pmol/L).
Derived reference intervals for thyroid function tests during the first trimester of pregnancy were: TSH, 0.02-2.15 mU/L; fT4, 10.4-17.8 pmol/L; and fT3, 3.3-5.7 pmol/L. If the non-pregnant TSH reference range was applied to the study participants, 344 women (16.0%) whose serum TSH concentration was within the first-trimester-specific reference range would be misclassified as having subclinical hyperthyroidism, and 98 women (4.5%) with a TSH concentration above the first-trimester-specific upper reference limit would not be identified.
The reference interval for TSH during the first trimester of pregnancy differs substantially from that for non-pregnant women, and applying the general laboratory reference range to pregnant women results in misclassification of thyroid status for 20.5% of women. Australian pathology laboratories should adopt pregnancy-specific reference intervals for thyroid function tests.
建立澳大利亚孕妇孕早期甲状腺功能检查的特定参考区间。
设计、地点和参与者：2006年10月和11月期间，从一家私立病理诊所收集了2159名孕妇（妊娠9 - 13周）的血清样本，用于孕早期筛查。采用化学发光免疫分析法（雅培ARCHITECT分析仪）测定血清促甲状腺激素（TSH）、游离甲状腺素（fT4）、游离三碘甲状腺原氨酸（fT3）、甲状腺过氧化物酶抗体（TPOAb）和甲状腺球蛋白抗体（TgAb）水平。
排除338名TPOAb或TgAb检测呈阳性的女性后，基于TSH、fT4和fT3的第2.5和第97.5百分位数确定参考区间；与非孕妇参考区间（TSH，0.40 - 4.0 mU/L；fT4，9 - 19 pmol/L；fT3，3.0 - 5.5 pmol/L）进行比较。
孕早期甲状腺功能检查得出的参考区间为：TSH，0.02 - 2.15 mU/L；fT4，10.4 - 17.8 pmol/L；fT3，3.3 - 5.7 pmol/L。如果将非孕妇TSH参考范围应用于研究参与者，344名（16.0%）血清TSH浓度在孕早期特定参考范围内的女性会被误诊为亚临床甲亢，98名（4.5%）TSH浓度高于孕早期特定参考上限的女性将未被识别。
孕早期TSH参考区间与非孕妇有显著差异，将一般实验室参考范围应用于孕妇会导致20.5%的女性甲状腺状态误诊。澳大利亚病理实验室应采用孕早期特定的甲状腺功能检查参考区间。
