ArticleArchives of endocrinology and metabolism2018
Maternal hypothyroxinemia in the first trimester of gestation and association with obstetric and neonatal outcomes and iron deficiency: a prospective Brazilian study.
Article in Archives of endocrinology and metabolism, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers, 3 of them syntheses that pooled it.
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Who cites it
6 citing papers in PubMed, 3 syntheses or guidelines pooled it.
- Association of iron status indicators with thyroid hormone concentrations during pregnancy: a systematic review and meta-analysis.Frontiers in endocrinology · 2025Pooled it
- Iron Deficiency, a Risk Factor of Thyroid Disorders in Reproductive-Age and Pregnant Women: A Systematic Review and Meta-Analysis.Frontiers in endocrinology · 2021Pooled it
- The Need for Dynamic Clinical Guidelines: A Systematic Review of New Research Published After Release of the 2017 ATA Guidelines on Thyroid Disease During Pregnancy and the Postpartum.Frontiers in endocrinology · 2020Pooled it
- Effects of isolated maternal hypothyroxinemia on adverse pregnancy outcomes.Archives of gynecology and obstetrics · 2022Article
- Insignificant Effect of Isolated Hypothyroxinemia on Pregnancy Outcomes During the First and Second Trimester of Pregnancy.Frontiers in endocrinology · 2020Article
- Selective screening for thyroid dysfunction in pregnant women: How often do low-risk women cease to be treated following the new guidelines of the American Thyroid Association?Archives of endocrinology and metabolism · 2018Article
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Authors and funding
3 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveTo evaluate the association of isolated hypothyroxinemia in the first trimester with obstetric and neonatal outcomes and iron deficiency. SUBJECTS AND
methodsThe study was prospective. Women who had become pregnant spontaneously were initially selected. Next, anti-thyroid peroxidase antibodies (TPOAb), free T4 (FT4), total T4 (TT4), TSH, and ferritin were measured. TPOAb-positive women were excluded. The final sample consisted of 596 women with serum TSH between 0.1 and 2.5 mIU/l. Hypothyroxinemia was defined as FT4 < 0.86 ng/dL and < 0.92 ng/dL, corresponding to the 5th and 10th percentiles, respectively, and TT4 < 7.8 ng/dL. None of the pregnant women was treated with levothyroxine until the end of pregnancy.
resultsThe women ranged in age from 18 to 36 years, with a median gestation of 9 weeks. T4 levels were not correlated with BMI or maternal TSH. Isolated hypothyroxinemia was observed in 4.3% (FT4 < 0.86 ng/dL), 9% (FT4 < 0.92 ng/dL), and 7% (TT4 < 7.8 ng/dL) of the pregnant women. The frequencies of obstetric and neonatal outcomes were similar in women with versus without hypothyroxinemia. In women without iron deficiency, 8.4%, 3.9%, and 6.5% had FT4 < 0.92 ng/dl, FT4 < 0.86 ng/dL and TT4 < 7.8 ng/dL, respectively. These frequencies of hypothyroxinemia were significantly higher among women with iron deficiency (20.7%, 14.8% and 17.2%, respectively).
conclusionsThis prospective Brazilian study found no association between isolated hypothyroxinemia in the first trimester of gestation and obstetric or neonatal outcomes, but an association was demonstrated with iron deficiency.
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