Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Apr 18;13(2):e230213.
doi: 10.1530/ETJ-23-0213. Print 2024 Apr 1.

Relationship between maternal obesity and first-trimester TSH in women with negative anti-TPO antibodies

Laura Croce  1   2 , Fausta Beneventi  3 , Federica Ripepi  1 , Irene De Maggio  3 , Alberto Malovini  4 , Camilla Bellingeri  3 , Francesca Coperchini  1 , Marsida Teliti  1   2 , Mario Rotondi  1   2 , Arsenio Spinillo  3 , Flavia Magri  1   2
Affiliations

Relationship between maternal obesity and first-trimester TSH in women with negative anti-TPO antibodies

Laura Croce et al. Eur Thyroid J. .

Abstract

Objective: Obesity is associated with increased thyroid-stimulating hormone (TSH) in non-pregnant subjects, but this phenomenon has not been fully characterized during pregnancy. Our aim was to evaluate the impact of BMI on first-trimester TSH in a wide cohort of pregnant women with negative anti-thyroperoxidase antibodies (AbTPO) and its implications on uterine artery pulsatility index (UtA-PI), a marker of early placentation.

Methods: The study included 2268 AbTPO-negative pregnant women at their first antenatal visit. Anamnestic data, BMI, TSH, anti-nuclear antibody (ANA) and extractable nuclear antigen (ENA) positivity and mean UtA-PI were collected.

Results: A total of 1693 women had normal weight, 435 were overweight and 140 were obese. Maternal age, ANA/ENA positivity, history of autoimmune diseases and familiar history of thyroid diseases were similar in the three groups. TSH was significantly higher in obese women (1.8 (IQR: 1.4-2.4) mU/L) when compared to normal weight (1.6 (IQR: 1.2-2.2) mU/L) and overweight (median: 1.6 (IQR: 1.2-2.2) mU/L) ones (P < 0.001). BMI was significantly related with the risk of having a TSH level ≥4 mU/L at logistic regression, independently from non-thyroid autoimmunity, smoking or familiar predisposition for thyroid diseases (OR: 1.125, 95% CI: 1.080-1.172, P < 0.001). A restricted cubic splines regression showed a non-linear relationship between BMI and TSH. Women with a TSH ≥4 mU/L had a higher UtA-PI, independently from BMI.

Conclusion: Overweight/obesity is significantly related with TSH serum levels in AbTPO-negative pregnant women, independently from the other risk factors for hypothyroidism during pregnancy. The increase of TSH levels could be clinically relevant, as suggested by its association with abnormal UtA-PI, a surrogate marker of abnormal placentation.

Keywords: TSH; hypothyroidism; obesity; pregnancy; thyroid.

PubMed Disclaimer

Conflict of interest statement

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the study reported.

Figures

Figure 1
Figure 1
Flow diagram of the study.
Figure 2
Figure 2
Scatterplot describing the relationship between BMI and TSH as continuous variables. Dots in gray correspond to single observations. The line in blue describes the non-linear relationship between BMI and TSH deriving from the regression model including only BMI, while the line in red describes the non-linear relationship between BMI and TSH deriving from the regression model including additional variables (i.e. holding constant the additional variables values in the model (familiar history of thyroid diseases = no, history of non-thyroidal autoimmune diseases = no, smoking status = not active)). Shaded areas represent 95% confidence intervals. RCS, restricted cubic spline; BMI, body mass index; TSH, thyroid-stimulating hormone.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Alexander EK, Pearce EN, Brent GA, Brown RS, Chen H, Dosiou C, Grobman WA, Laurberg P, Lazarus JH, Mandel SJ, et al.2017 Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and the postpartum. Thyroid 201727315–389. (10.1089/thy.2016.0457) - DOI - PubMed
    1. Dong AC & Stagnaro-Green A. Differences in diagnostic criteria mask the true prevalence of thyroid disease in pregnancy: a systematic review and meta-analysis. Thyroid 201929278–289. (10.1089/thy.2018.0475) - DOI - PubMed
    1. Rotondi M Chiovato L Pacini F Bartalena L & Vitti P. Management of subclinical hypothyroidism in pregnancy: a comment from the Italian society of endocrinology and the Italian Thyroid Association to the 2017 American Thyroid Association guidelines-"the Italian way". Thyroid 201828551–555. (10.1089/thy.2017.0424) - DOI - PubMed
    1. Chen J Zhu J Huang X Zhao S Xiang H Zhou P Zhou T & Xu Z. Subclinical hypothyroidism with negative for thyroid peroxidase antibodies in pregnancy: intellectual development of offspring. Thyroid 202232449–458. (10.1089/thy.2021.0374) - DOI - PubMed
    1. Magri F Bellingeri C De Maggio I Croce L Coperchini F Rotondi M Chiovato L Spinillo A & Beneventi F. A first-trimester serum TSH in the 4–10 mIU/L range is associated with obstetric complications in thyroid peroxidase antibody-negative women. Journal of Endocrinological Investigation 2023461407–1414. (10.1007/s40618-022-01996-z) - DOI - PubMed