Maternal hypothyroxinemia in the first trimester of gestation and association with obstetric and neonatal outcomes and iron deficiency: a prospective Brazilian study
Arch. endocrinol. metab. (Online)
;
62(3): 332-336, May-June 2018. tab
Article
in English
| LILACS
| ID: biblio-950064
ABSTRACT
ABSTRACT Objective:
To evaluate the association of isolated hypothyroxinemia in the first trimester with obstetric and neonatal outcomes and iron deficiency. Subjects andmethods:
The 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.Results:
The 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).Conclusions:
This 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.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Pregnancy Complications
/
Thyroid Diseases
/
Thyroxine
/
Pregnancy Outcome
/
Anemia, Iron-Deficiency
Type of study:
Observational study
/
Risk factors
Limits:
Adult
/
Female
/
Humans
/
Infant, Newborn
/
Pregnancy
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Arch. endocrinol. metab. (Online)
Journal subject:
Endocrinology
/
Metabolism
Year:
2018
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Fundação Universidade de Itaúna/BR
/
Santa Casa de Belo Horizonte/BR
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