Thyroid stimulating hormone (TSH) ≥2.5mU/l in early pregnancy: Prevalence and subsequent outcomes.

Abstract

OBJECTIVE:

There remains controversy over how women with abnormal thyroid function tests in pregnancy should be classified. In this study we assessed the proportion of women with thyroid stimulating hormone (TSH)≥2.5mU/l in a large obstetric cohort, and examined how many have gone on to develop thyroid disease in the years since their pregnancy.

STUDY DESIGN:

4643 women were recruited and samples taken in early pregnancy between 2007 and 2010. Thyroid function tests were analysed in 2014; in women with raised TSH computerised health records and prescription databases were used to identify thyroid disease detected since pregnancy.

RESULTS:

58 women (1.5%) had a TSH over 5mU/l and 396 women (10.3%) had TSH between 2.5 and 5mU/l. Women with TSH>5mU/l delivered infants of lower birthweight than those with TSH<2.5mU/l; there were no other differences in obstetric outcomes between the groups. Of those who have had thyroid tests since their pregnancy, 78% of those with TSH>5mU/l and 19% of those with TSH between 2.5 and 5mU/l have gone on to be diagnosed with thyroid disease.

CONCLUSIONS:

Using a TSH cut-off of 2.5mU/l in keeping with European and US guidelines means that over 12% of women in this cohort would be classified as having subclinical hypothyroidism. Treatment and monitoring of these women would have major implications for planning of obstetric services.

• Authors: David M Carty, Flora Doogan, Paul Welsh, Anna F Dominiczak, Christian Delles
• Journal: European journal of obstetrics, gynecology, and reproductive biology (Eur J Obstet Gynecol Reprod Biol) Vol. 210 Pg. 366-369 (Mar 2017) ISSN: 1872-7654 [Electronic] Ireland
• PMID: 28153744 (Publication Type: Journal Article)
• Copyright: Copyright © 2017 Elsevier B.V. All rights reserved.

Chemical References

• Thyrotropin

Topics

• Adult
• Female
• Humans
• Hypothyroidism (blood, epidemiology)
• Pregnancy
• Pregnancy Complications (blood, epidemiology)
• Pregnancy Trimester, First (blood)
• Scotland (epidemiology)
• Thyrotropin (blood)
• Young Adult