ArticleEndocrine connections2021
Maternal adiposity, smoking, and thyroid function in early pregnancy.
Article in Endocrine connections, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
9 citing papers in PubMed, 2 syntheses or guidelines pooled it, 15 citations in OpenAlex.
- Risk Factors for Thyroid Function Test Abnormalities During Pregnancy: A Systematic Review of the Literature to Validate Current Risk Factors and Identify Novel Ones.Thyroid : official journal of the American Thyroid Association · 2025Pooled it
- TSH and FT4 Reference Intervals in Pregnancy: A Systematic Review and Individual Participant Data Meta-Analysis.The Journal of clinical endocrinology and metabolism · 2022Pooled it
- Cardiovascular Risk Determinants in Euthyroid Patients with Obesity: The Strange Case of TSH in Primary Prevention.Journal of clinical medicine · 2026Article
- The association between maternal FT3/FT4 ratio in early pregnancy and adverse neonatal outcomes: a retrospective cohort study.Frontiers in endocrinology · 2026Article
- Birth weight and placental weight in children born to mothers with hypothyroidism.European thyroid journal · 2025Article
- Autoimmune Thyroid Disease and Pregnancy: The Interaction Between Genetics, Epigenetics and Environmental Factors.Journal of clinical medicine · 2024Review
- Relationship between maternal obesity and first-trimester TSH in women with negative anti-TPO antibodies.European thyroid journal · 2024Article
- Thyroid dysfunction during gestation and gestational diabetes mellitus: a complex relationship.Journal of endocrinological investigation · 2023Review
- Screening for thyroid disease in pregnancy: a study of Danish clinical practice.Thyroid research · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveA high activity of the deiodinase type 2 has been proposed in overweight, obese, and smoking pregnant women as reflected by a high triiodothyronine (T3)/thyroxine (T4) ratio. We speculated how maternal adiposity and smoking would associate with different thyroid function tests in the early pregnancy.
designCross-sectional study within the North Denmark Region Pregnancy Cohort.
methodsMaternal thyroid-stimulating hormone (TSH), total T4 (TT4), total T3 (TT3), free T4 (fT4), and free T3 (fT3) were measured in stored blood samples (median gestational week 10) by an automatic immunoassay. Results were linked to nationwide registers, and live-birth pregnancies were included. The associations between maternal adiposity (overweight or obese), smoking, and log-transformed TSH, fT3/fT4 ratio, and TT3/TT4 ratio were assessed using multivariate linear regression and reported as adjusted exponentiated β coefficient (aβ) with 95% CI. The adjusted model included maternal age, parity, origin, week of blood sampling, and diabetes.
resultsAltogether 5529 pregnant women were included, and 40% were classified with adiposity, whereas 10% were smoking. Maternal adiposity was associated with higher TSH (aβ 1.13 (95% CI 1.08-1.20)), whereas maternal smoking was associated with lower TSH in the early pregnancy (0.875 (0.806-0.950)). Considering the T3/T4 ratio, both maternal adiposity (fT3/fT4 ratio: 1.06 (1.05-1.07); TT3/TT4 ratio: 1.07 (1.06-1.08)) and smoking (fT3/fT4 ratio: 1.07 (1.06-1.09); TT3/TT4 ratio: 1.10 (1.09-1.12)) were associated with a higher ratio.
conclusionsIn a large cohort of Danish pregnant women, adiposity and smoking showed opposite associations with maternal TSH. On the other hand, both conditions were associated with a higher T3/T4 ratio in early pregnancy, which may reflect altered deiodinase activity.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.