Trimester- and Assay-Specific Thyroid Reference Intervals for Pregnant Women in China

Jinfang Xing; Enwu Yuan; Jing Li; Yuchao Zhang; Xiangying Meng; Xia Zhang; Shouhua Rong; Zhongxing Lv; Yuan Tian; Liting Jia

doi:10.1155/2016/3754213

International Journal of Endocrinology (Jan 2016)

Trimester- and Assay-Specific Thyroid Reference Intervals for Pregnant Women in China

Jinfang Xing,
Enwu Yuan,
Jing Li,
Yuchao Zhang,
Xiangying Meng,
Xia Zhang,
Shouhua Rong,
Zhongxing Lv,
Yuan Tian,
Liting Jia

Affiliations

Jinfang Xing: Clinical Laboratory Department, The Third Affiliated Hospital of Zhengzhou University, No. 7 Front Kangfu Street, Er’qi Distric, Zhengzhou 450052, China
Enwu Yuan: Clinical Laboratory Department, The Third Affiliated Hospital of Zhengzhou University, No. 7 Front Kangfu Street, Er’qi Distric, Zhengzhou 450052, China
Jing Li: Clinical Laboratory Department, The Third Affiliated Hospital of Zhengzhou University, No. 7 Front Kangfu Street, Er’qi Distric, Zhengzhou 450052, China
Yuchao Zhang: Clinical Laboratory Department, The Third Affiliated Hospital of Zhengzhou University, No. 7 Front Kangfu Street, Er’qi Distric, Zhengzhou 450052, China
Xiangying Meng: Clinical Laboratory Department, The Third Affiliated Hospital of Zhengzhou University, No. 7 Front Kangfu Street, Er’qi Distric, Zhengzhou 450052, China
Xia Zhang: Clinical Laboratory Department, The Third Affiliated Hospital of Zhengzhou University, No. 7 Front Kangfu Street, Er’qi Distric, Zhengzhou 450052, China
Shouhua Rong: Clinical Laboratory Department, The Third Affiliated Hospital of Zhengzhou University, No. 7 Front Kangfu Street, Er’qi Distric, Zhengzhou 450052, China
Zhongxing Lv: Clinical Laboratory Department, The Third Affiliated Hospital of Zhengzhou University, No. 7 Front Kangfu Street, Er’qi Distric, Zhengzhou 450052, China
Yuan Tian: Clinical Laboratory Department, The Third Affiliated Hospital of Zhengzhou University, No. 7 Front Kangfu Street, Er’qi Distric, Zhengzhou 450052, China
Liting Jia: Clinical Laboratory Department, The Third Affiliated Hospital of Zhengzhou University, No. 7 Front Kangfu Street, Er’qi Distric, Zhengzhou 450052, China

DOI: https://doi.org/10.1155/2016/3754213
Journal volume & issue: Vol. 2016

Abstract

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Objective. The guidelines of the American Thyroid Association (ATA) recommend an upper limit reference interval (RI) of thyroid stimulating hormone (TSH) of 2.5 mIU/L in the first trimester of pregnancy and 3.0 mIU/L in subsequent trimesters, but some reported ranges in China are significantly higher. Our study aimed to establish trimester- and assay-specific RIs for thyroid hormones in normal pregnant Chinese women. Methods. In this cross-sectional study, 2540 women with normal pregnancies (first trimester, n=398; second trimester, n=797; third trimester, n=1345) and 237 healthy nonpregnant control subjects were recruited. Serum TSH, free thyroxin (FT4), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) levels were determined by automated chemiluminescence with an Immulite 2000 system (Siemens, Erlangen, Germany). After outliers were excluded, the 2.5–97.5th percentiles were used to define the RIs. Results. The RIs of thyroid function in the first, second, and third trimesters of pregnancy and in nonpregnant controls were 0.07–3.96, 0.27–4.53, 0.48–5.40, and 0.69–5.78 mIU/L for TSH and 9.16–18.12, 8.67–16.21, 7.80–13.90, and 8.24–16.61 pmol/L for FT4, respectively. Conclusion. The trimester- and assay-specific RIs of thyroid function during pregnancy differed between trimesters, which suggests that it is advisable to detect and avoid misclassification of thyroid dysfunction during pregnancy for women in Henan, China.

Published in International Journal of Endocrinology

ISSN: 1687-8337 (Print); 1687-8345 (Online)
Publisher: Hindawi Limited
Country of publisher: United Kingdom
LCC subjects: Medicine: Internal medicine: Specialties of internal medicine: Diseases of the endocrine glands. Clinical endocrinology
Website: https://www.hindawi.com/journals/ije/

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