The prevalence of maternal hypothyroidism in first trimester screening from 11 to 14 weeks of gestation
Language English Country Czech Republic Media print-electronic
Document type Comparative Study, Journal Article, Observational Study
PubMed
30401989
DOI
10.5507/bp.2018.063
Knihovny.cz E-resources
- Keywords
- gestation, hypothyroidism, immunoassay, pregnancy, thyroid disease,
- MeSH
- Adult MeSH
- Hypothyroidism blood diagnosis MeSH
- Immunoassay methods MeSH
- Iodide Peroxidase immunology MeSH
- Pregnancy Complications blood diagnosis MeSH
- Humans MeSH
- Antibodies metabolism MeSH
- Pregnancy Trimester, First MeSH
- Retrospective Studies MeSH
- Pregnancy, Twin physiology MeSH
- Pregnancy MeSH
- Thyrotropin metabolism MeSH
- Thyroxine metabolism MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Pregnancy MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Observational Study MeSH
- Comparative Study MeSH
- Names of Substances
- Iodide Peroxidase MeSH
- Antibodies MeSH
- Thyrotropin MeSH
- Thyroxine MeSH
AIM: The aim of this study was to determine the prevalence of maternal hypothyroidism in the first trimester from 11 to 14 weeks of gestation according to the American Thyroid Association (ATA) guidelines from 2017 and to compare the rates for singleton and twin pregnancies. METHODS: A total of 4965 consecutive Caucasian singleton pregnancies and 109 Caucasian twin pregnancies were included in the investigation. Patients with a history of thyroid gland disorder were excluded. Subclinical maternal hypothyroidism was defined as a thyroid stimulating hormone (TSH) concentration above the 97.5th percentile and free thyroxine (fT4) within the range of a reference population of women at 11-14 weeks of gestation. Overt maternal hypothyroidism was defined as a TSH concentration above the 97.5th percentile and an fT4 below the 2.5th percentile of the reference population.TSH, fT4, and anti thyroid peroxidase antibody (TPOAb) were measured by immunochemiluminescent assays on an 16200 Abbott Architect analyzer. RESULTS: The prevalence of hypothyroidism for twin pregnancies was no higher than that for singleton pregnancies; 6.42% (7/109) vs. 5.32% (264/4965), respectively; P=0.61. All twin pregnancies were subclinical. Singleton hypothyroid pregnancies included 4.91% (244 cases) of subclinical and 0.41% (20 cases) of overt hypothyroidism. The prevalence of TPOAb positive hypothyroid women for twin pregnancies and singleton pregnancies was 71% (5/7) vs. 52% (137/264 cases), respectively but the differences were not statistically significant; P=0.31. CONCLUSION: Each first trimester screening center should establish its TSH and fT4 reference ranges. Our center had higher upper reference limits of TSH than that of the universally fixed limit of 2.5 mU/L, which led to a lower measured prevalence of maternal hypothyroidism. A large number of hypothyroid women were TPOAb positive.
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