uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Targeted Thyroid Testing During Pregnancy in Clinical Practice
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Obstetrics and Gynaecology.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Obstetrics and Gynaecology.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Biochemical endocrinology.
Show others and affiliations
2014 (English)In: Obstetrics and Gynecology, ISSN 0029-7844, E-ISSN 1873-233X, Vol. 124, no 1, 10-15 p.Article in journal (Refereed) Published
Abstract [en]

OBJECTIVE:To evaluate the efficacy of a targeted thyroid testing approach during pregnancy in clinical practice.

METHODS:This is a retrospective cohort study performed within Uppsala County, Sweden. Data were derived from the population-based Uppsala Biobank of Pregnant Women, in which blood samples are collected in conjunction with the routine ultrasound screening in gestational week 17-19. For this study, 5,254 pregnant women with an estimated date of delivery between January 1, 2009, and December 31, 2011, were included. On review of their medical records, women who were tested for thyroid dysfunction during pregnancy in clinical practice were identified (n=891). From the remaining untested women, 1,006 women were randomly selected for analyses of thyrotropin (TSH), free thyroxine levels, and thyroid peroxidase antibodies. Thyroid-stimulating hormone levels in both groups were analyzed with regard to trimester-specific upper reference levels as recommended by the International Endocrine Society Guidelines.

RESULTS:The proportion of trimester-specific TSH elevation was 12.6% in the targeted thyroid testing group and 12.1% in the untested group (P=.8; odds ratio [OR] 1.04, 95% confidence interval [CI] 0.79-1.37). The proportion of overt hypothyroidism was 1.1% and 0.7% in the groups, respectively (P=.4; OR 1.57, 95% CI 0.55-4.45).

CONCLUSIONS:The prevalence of trimester-specific elevated TSH and overt hypothyroidism was equal in targeted thyroid tested and untested women. When implemented in clinical practice, targeted thyroid testing is unsatisfactory. If ongoing studies provide support for treatment of pregnant women with elevated TSH, universal thyroid testing appears the most reasonable approach.

Place, publisher, year, edition, pages
2014. Vol. 124, no 1, 10-15 p.
National Category
Obstetrics, Gynecology and Reproductive Medicine
Identifiers
URN: urn:nbn:se:uu:diva-228696DOI: 10.1097/AOG.0000000000000344ISI: 000337734000004OAI: oai:DiVA.org:uu-228696DiVA: diva2:734803
Available from: 2014-07-21 Created: 2014-07-21 Last updated: 2017-12-05Bibliographically approved
In thesis
1. Hypothyroidism and Pregnancy
Open this publication in new window or tab >>Hypothyroidism and Pregnancy
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Hypothyroidism is a common endocrine disorder affecting women of reproductive age. On a global level, iodine deficiency is still the most common cause of hypothyroidism. Also genetic variations, in particular SNP rs4704397 in the PDE8B gene, are responsible for a significant proportion of TSH variations.  Untreated hypothyroidism has significant adverse effects on pregnancy and fetal outcome. Most international guidelines suggest targeted thyroid testing in pregnant women with risk factors for thyroid disturbances.

In a case-control study, an association between homozygous A/A as well as homozygous G/G carriers of SNP rs 4704397 in PDE8B and recurrent miscarriage was found. The explanation for this association is unknown.

In a nationwide survey, all guidelines for thyroid testing and management of hypothyroidism during pregnancy in Sweden were collected and compared with international guidelines. The local guidelines were variable and poorly compliant with the international guidelines.

In a follow-up in one district, 5,254 pregnant women were included for subsequent review of their medical reports. We found a targeted thyroid testing rate of 20.1% in clinical practice, with an overall frequency of women with trimester-specific elevated TSH of 18.5%. More disturbingly, half of the women who were on levothyroxine treatment at the time of conception had an elevated TSH level at thyroid testing.

In a subsequent cohort study of the 5,254 women, we found the prevalence of trimester-specific elevated TSH and overt hypothyroidism to be equal in targeted thyroid tested and untested women.

In a cross-sectional study, a median urinary iodine concentration (UIC) of 98 μg/l was found in the study population. According to WHO/UNICEF/IGN criteria, the population-based median UIC during pregnancy should be 150-249 μg/l.

In conclusion, genetic variations may contribute to adverse pregnancy outcomes. In clinical practice, thyroid testing and the management of hypothyroidism during pregnancy is unsatisfactory, regarding the whole chain from development of local guidelines to their implementation and to targeted thyroid testing. Moreover, our results indicate insufficient iodine status in the pregnant population of Sweden.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2015. 69 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 1081
Keyword
phosphodiesterase 8B, recurrent miscarriage, single nucleotide polymorphism, thyroid, guidelines, hypothyroidism, pregnancy, survey, thyroid testing, screening, iodine, iodine deficiency, median urinary iodine concentration
National Category
Obstetrics, Gynecology and Reproductive Medicine
Research subject
Obstetrics and Gynaecology
Identifiers
urn:nbn:se:uu:diva-247090 (URN)978-91-554-9201-4 (ISBN)
Public defence
2015-05-08, Rosénsalen, Akademiska sjukhuset, ingång 95/96. Barn- och kvinnosjukhuset. NBV (nedre bottenvåning)., Uppsala, 09:00 (Swedish)
Opponent
Supervisors
Available from: 2015-04-17 Created: 2015-03-13 Last updated: 2015-07-07

Open Access in DiVA

No full text

Other links

Publisher's full text

Authority records BETA

Granfors, MichaelaÅkerud, HelenaStridsberg, MatsWikström, Anna-KarinSundström-Poromaa, Inger

Search in DiVA

By author/editor
Granfors, MichaelaÅkerud, HelenaStridsberg, MatsWikström, Anna-KarinSundström-Poromaa, Inger
By organisation
Obstetrics and GynaecologyBiochemical endocrinology
In the same journal
Obstetrics and Gynecology
Obstetrics, Gynecology and Reproductive Medicine

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 514 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf