Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2021;43(10):736-742
Thyroid diseases are the second most common endocrine disorders in the reproductive period of women. They can be associated with intrauterine growth restriction (IUGR), preterm delivery, low Apgar score, low birthweight (LBW) or fetal death. The aim of the present study is to explore thyroid dysfunction and its relationship with some poor perinatal outcomes (Apgar Score, low birthweight, and preterm delivery).
Dried blood spot samples from 358 healthy pregnant women were analyzed for thyroid stimulating hormone (TSH), total thyroxine (TT4), and thyroglobulin (Tg). Neonatal data were collected upon delivery. Four groups were formed based on thyroid function tests (TFTs).
Of the 358 tested women, 218 (60.72%) were euthyroid. Isolated hypo thyroxinemia was present in 132 women (36.76%), subclinical hyperthyroidism in 7 women (1.94%), and overt hypothyroidism in 1 (0.28%). The perinatal outcomes IUGR (p = 0.028) and Apgar score 1 minute (p = 0.015) were significantly different between thyroid function test [TFT]-distinct groups. In the multiple regression analysis, TT4 showed a statistically significant inverse predictive impact on LBW (p < 0.0001), but a positive impact of Tg on LBW (p = 0.0351).
Thyroid hormones alone do not have a direct impact on neonatal outcomes, but the percentage of their participation in the total process cannot be neglected. Based on the regression analysis, we can conclude that TT4 and Tg can be used as predictors of neonatal outcome, expressed through birthweight and Apgar score. The present study aims to contribute to determine whether a test for thyroid status should become routine screening during pregnancy.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2007;29(9):478-483
DOI 10.1590/S0100-72032007000900007
PURPOSE: to quantify the presence of antithyroperoxidase (anti-TPO) and antithyroglobulin (anti-TG) antibodies, and the plasmatic concentrations of thyrotropin (TSH) and free thyroxine (FT4) in normal pregnant women. METHODS: a hundred twenty-seven pregnant women, residing in São Paulo, aged from 14 to 44 years old and gestational age > 16 weeks, determined by ultrasound performed before the 20th week of pregnancy were included in a transversal study performed in the prenatal clinic of Santa Casa de Misericórdia de São Paulo, from January 2003 to September 2004. Pregnant women using medicines or with thyroidopathy history were excluded. Antithyroperoxidase and antithyroglobulin antibodies were quantified by chemiluminescence immunoassay. The immunofluorimetry technique by time-resolved was used for determining the thyrotrophin and free thyroxine. The Student's t test, with significance of 5%, was used for analyzing the results. RESULTS: the frequency of antithyroid antibodies was 12.6% (8.6% of anti-TPO antibodies, and 4.6% of anti-TG antibodies). The average of TSH concentrations was 2.13±1.0 µU/ml, and the average of T4L was 0.9±0.5 ng/dl. It was observed alteration of the thyroid function in ten pregnant women (8%). Three of them had diagnosis of hypothyroidism: one in the clinical form of the disease, with increased TSH and decreased FT4; two in the subclinical form with increased TSH and normal FT4. Five presented decreased TSH and increased FT4, consistent with clinical hyperthyroidism and two were diagnosed with subclinical hyperthyroidism, with decreased TSH concentrations only. CONCLUSIONS: the frequency of antithyroid antibodies was 12.6% in pregnant women, the antithyroperoxidase antibodies being predominant over the antithyroglobulin antibodies. It was observed some thyroid dysfunction in 8% of the cases with alterations of TSH and/or T4L.