title: Screening strategies for thyroid disorders in the first and second trimester of pregnancy in China.
abstract: BACKGROUND
  Thyroid dysfunction during pregnancy is associated with multiple adverse outcomes, but whether all women should be screened for thyroid disorders during pregnancy remains controversial.
  
  
  OBJECTIVE
  To evaluate the effectiveness of the targeted high risk case-finding approach for identifying women with thyroid dysfunction during the first and second trimesters of pregnancy.
  
  
  METHODS
  Levels of thyroid stimulating hormone (TSH), free thyroxine (FT4), and thyroid peroxidase antibodies (TPOAb) were measured in 3882 Chinese women during the first and second trimester of pregnancy. All tested women were divided into the high risk or non-high risk groups, based on their history, findings from physical examination, or other clinical features suggestive of a thyroid disorder. Diagnosis of thyroid disorders was made according to the standard trimester-specific reference intervals. The prevalence of thyroid disorders in each group was determined, and the feasibility of a screening approach focusing exclusively on high risk women was evaluated to estimate the ability of finding women with thyroid dysfunction.
  
  
  RESULTS
  The prevalence of overt hypothyroidism or hyperthyroidism in the high risk group was higher than in the non-high risk group during the first trimester (0.8% vs 0, χ2 = 7.10, p = 0.008; 1.6% vs 0.2%, χ2 = 7.02, p = 0.008, respectively). The prevalence of hypothyroxinemia or TPOAb positivity was significantly higher in the high risk group than in the non-high risk group during the second trimester (1.3% vs 0.5%, χ2 = 4.49, p = 0.034; 11.6% vs 8.4%, χ2 = 6.396, p = 0.011, respectively). The total prevalence of hypothyroidism or hyperthyroidism and the prevalence of subclinical hypothyroidism or hyperthyroidism were not statistically different between the high risk and non-high risk groups, for either the first or second trimester.
  
  
  CONCLUSIONS
  The high risk screening strategy failed to detect the majority of pregnant women with thyroid disorders. Therefore, we recommend universal screening of sTSH, FT4, and TPOAb during the first trimester and second trimester of pregnancy.
authors.affiliation: Department of Endocrinology, The Third Hospital Affiliate to Wenzhou Medical University, Ruian, Zhejiang, China; Ruian Center of the Chinese-American Research Institute for Diabetic Complications, the Third Affiliated Hospital of the Wenzhou Medical University, Ruian, Zhejiang, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.affiliation: Chinese-American Research Institute for Diabetic Complications, School of Pharmaceutical Sciences, Key Laboratory of Biotechnology Pharmaceutical Engineering, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Minglong
authors.initials: M
authors.lastname: Shao
authors.affiliation: Department of Endocrinology, The Third Hospital Affiliate to Wenzhou Medical University, Ruian, Zhejiang, China; Ruian Center of the Chinese-American Research Institute for Diabetic Complications, the Third Affiliated Hospital of the Wenzhou Medical University, Ruian, Zhejiang, China.
authors.forename: Liangmiao
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Endocrinology, The Third Hospital Affiliate to Wenzhou Medical University, Ruian, Zhejiang, China; Ruian Center of the Chinese-American Research Institute for Diabetic Complications, the Third Affiliated Hospital of the Wenzhou Medical University, Ruian, Zhejiang, China.
authors.forename: Qingshou
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Endocrinology, The Third Hospital Affiliate to Wenzhou Medical University, Ruian, Zhejiang, China; Ruian Center of the Chinese-American Research Institute for Diabetic Complications, the Third Affiliated Hospital of the Wenzhou Medical University, Ruian, Zhejiang, China.
authors.forename: Lechu
authors.initials: L
authors.lastname: Yu
authors.affiliation: Department of Endocrinology, The Third Hospital Affiliate to Wenzhou Medical University, Ruian, Zhejiang, China; Ruian Center of the Chinese-American Research Institute for Diabetic Complications, the Third Affiliated Hospital of the Wenzhou Medical University, Ruian, Zhejiang, China.
authors.forename: Lingqiao
authors.initials: L
authors.lastname: Cai
authors.affiliation: Department of Endocrinology, The Third Hospital Affiliate to Wenzhou Medical University, Ruian, Zhejiang, China; Ruian Center of the Chinese-American Research Institute for Diabetic Complications, the Third Affiliated Hospital of the Wenzhou Medical University, Ruian, Zhejiang, China.
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Chinese-American Research Institute for Diabetic Complications, School of Pharmaceutical Sciences, Key Laboratory of Biotechnology Pharmaceutical Engineering, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Endocrinology, The Third Hospital Affiliate to Wenzhou Medical University, Ruian, Zhejiang, China; Ruian Center of the Chinese-American Research Institute for Diabetic Complications, the Third Affiliated Hospital of the Wenzhou Medical University, Ruian, Zhejiang, China.
authors.forename: Xuemian
authors.initials: X
authors.lastname: Lu
mesh_terms: D000328:Adult; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D011256:Pregnancy Outcome / Q000453:epidemiology; D011261:Pregnancy Trimester, First / Q000097:blood; D011262:Pregnancy Trimester, Second / Q000097:blood; D011296:Prenatal Diagnosis / Q000379:methods* / Q000706:statistics & numerical data; D015995:Prevalence; D013959:Thyroid Diseases / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D013960:Thyroid Function Tests; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D055815:Young Adult
chemical_list: D013972:Thyrotropin; D013974:Thyroxine