Periconceptional changes in thyroid function: a longitudinal study

Public Deposited
Analytics

Downloadable Content

Download PDF
Request Version for Screen Reader
Creator
  • Balthazar, Ursula
    • Other Affiliation: Anchorage Women's Clinic, Anchorage, AK, USA
  • Steiner, Anne Z
    • Affiliation: School of Medicine, Department of Obstetrics and Gynecology
Abstract
  • Background: Limitations in our current knowledge of normative physiologic changes in thyroid function during the periconception window narrow our ability to establish an optimal approach to screening and diagnosis of thyroid disease in pregnant women. The objective of this study was to characterize changes in thyroid function during the transition from the pre-pregnant to pregnant state in normal fertile women. Methods: Women (N = 60) ages 30-42 years without a history of thyroid disease, who were planning pregnancy, were observed prospectively before and during early pregnancy. Thyroid function (thyroid stimulating hormone, TSH and free thyroxine, FT4) was measured before conception and between 6 and 9 weeks gestation. Prepregnancy samples were analyzed for thyroid antibodies. Bivariate analyses and longitudinal curves (general estimating equation models) were used to analyze changes in thyroid function during the periconception window by antibody status. Results: Pre-pregnancy TSH values were significantly higher than early pregnancy TSH (p < 0.001), but FT4 values did not differ (p = 0.53). TSH declined as gestational age increased (P < 0.01). Thyroid antibody positive women had a higher pre-pregnancy TSH compared to antibody negative women (p < 0.01). Periconceptional change in thyroid function was more variable among women with antibodies (p < 0.001). 50% of women with elevated prepregnancy TSH values (TSH > 3.0 mIU/L) had normal TSH values (TSH < 2.5 mIU/L) in pregnancy. Conclusions: TSH values decline during the transition from pre-pregnancy to early pregnancy. The change in TSH appears to be less predictable in women with thyroid antibodies. Periconceptional changes in thyroid function should be considered in formulating prenatal thyroid screening guidelines.
Date of publication
DOI
Identifier
Resource type
  • Article
Rights statement
  • In Copyright
Rights holder
  • Ursula Balthazar et al.; licensee BioMed Central Ltd.
License
Journal title
  • Reproductive Biology and Endocrinology
Journal volume
  • 10
Journal issue
  • 1
Page start
  • 20
Language
  • English
Is the article or chapter peer-reviewed?
  • Yes
ISSN
  • 1477-7827
Bibliographic citation
  • Reproductive Biology and Endocrinology. 2012 Mar 21;10(1):20
Publisher
  • BioMed Central Ltd
Access right
  • Open Access
Date uploaded
  • August 23, 2012

Relations

Parents:

This work has no parents.

Items

Thumbnail Title Date Uploaded Visibility Actions
file details 1477-7827-10-20.pdf 2019-05-06 Public Download
file details 1477-7827-10-20.xml 2019-05-06 Public Download