Tireóide e gravidez

Abstract

A gravidez está associada com a necessidade aumentada de secreção hormonal pela tireóide desde as primeiras semanas após a concepção. Para que esta maior demanda ocorra, a gestação induz uma série de alterações fisiológicas que afetam a função tireoidiana e, portanto, os testes de avaliação da função glandular. Para as mulheres grávidas normais que vivem em áreas suficientes em iodo, este desafio em ajustar a liberação de hormônios tireoidianos para o novo estado de equilíbrio e manter até o término da gestação, geralmente, ocorre sem dificuldades. entretanto, em mulheres com a capacidade funcional da tireóide prejudicada por alguma doença tireoidiana ou naquelas que residem em áreas de insuficiência iódica, isso não ocorre. o manejo de disfunções tireoidianas durante a gestação requer considerações especiais, pois tanto o hipotireoidismo quanto o hipertireoidismo podem levar a complicações maternas e fetais. Além disso, nódulos tireoidianos são detectados, com certa freqüência, em gestantes, o que pode gerar a necessidade do diagnóstico diferencial entre benignos e malignos ainda durante a gestação. ABSTRACT Thyroid and Pregnancy.Pregnancy is associated with an increased requirement of hormone secretion by the thyroid, within the first weeks after conception. to this greater demand to occurs, pregnancy induces a series of physiological changes that affect thyroid function and, consequently, the tests of glandular function. For normal pregnant women living in areas with a sufficient supply of iodine, this challenge regarding the adjustment of thyroid hormone releases to this new state of equilibrium and its maintenance until the end of pregnancy it meets no difficulties. However, among women with impaired thyroid function due to some thyroid disease or among women residing in areas with an insufficient iodine supply, this does not occur. the management of thyroid dysfunction during gestation requires special considerations, since both hypothyroidism and hyperthyroidism can lead to maternal and fetal complications. in addition, thyroid nodules are detected at reasonable frequency among pregnant women, a fact that requires a differential diagnosis between benign and malignant growths during the pregnancy itself.

Diabetes Mellitus Na Gestação: A Indução Do Parto Aumenta a Taxa De Cesariana?

“…Apesar da produção de HTs pelo próprio feto, estudos atuais comprovam que HTs maternos atravessam a barreira placentária e sugerem grande importância para a formação cerebral durante o segundo trimestre de gestação, que é quando o suprimento de HTs advém primariamente da passagem materna. Um caso não-controlado de hipotireoidismo materno (com baixos níveis de T4) durante essa fase poderia, portanto, resultar em sequelas neurológicas irreversíveis na criança (MACIEL et al, 2008).…”

Melatonin on hypothyroidism and gonadal development in rats: a review

“…Hypothyroidism is common in adult and reproductive women, with a prevalence of 2% in the worldwide female population ( Hapon et al, 2010 ). The incidence of hypothyroidism during pregnancy is between 0.3% and 2.5% ( Idris et al ., 2005 ), having profound repercussions on gestation and fetal formation ( Maciel & Magalhães, 2008 ). During gestation, the thyroid is initially stimulated by high concentrations of human chorionic gonadotrophin (hCG); thus, maintaining maternal euthyroidism during gestation and lactation, which is critical for fetal growth and development ( Maciel & Magalhães, 2008 ), since the hormones produced by this gland are involved in the formation of organs such as the skin ( Amerion et al ., 2013 ), brain ( Morreale de Escobar et al ., 2004 ) e testis ( Wagner et al ., 2008 ) of the fetuses.…”

“…The incidence of hypothyroidism during pregnancy is between 0.3% and 2.5% ( Idris et al ., 2005 ), having profound repercussions on gestation and fetal formation ( Maciel & Magalhães, 2008 ). During gestation, the thyroid is initially stimulated by high concentrations of human chorionic gonadotrophin (hCG); thus, maintaining maternal euthyroidism during gestation and lactation, which is critical for fetal growth and development ( Maciel & Magalhães, 2008 ), since the hormones produced by this gland are involved in the formation of organs such as the skin ( Amerion et al ., 2013 ), brain ( Morreale de Escobar et al ., 2004 ) e testis ( Wagner et al ., 2008 ) of the fetuses. Hypothyroidism is associated with several menstrual abnormalities, anovulation and hyperprolactinemia ( Sanyal & Raychaudhury, 2016 ), resulting in a high rate of miscarriages, premature births, placental rupture, and weight-related neonatal deficiencies ( Amerion et al ., 2013 ).…”

“…Hypothyroidism is divided into two different biochemical types: overt, where the thyroid-stimulating hormone (TSH) concentrations are above the reference range and free thyroxine concentrations below regular range or subclinical, where although the TSH concentrations are above the reference range, free thyroxine concentrations are within the normal range (Chaker et al, 2017). This disorder is present in 2% of the world's female population (Hapon et al, 2010), interfering directly in gestation and fetal formation (Maciel & Magalhães, 2008).…”

Region-specific reference intervals for TSH in pregnancy: time for changes in Brazil

“…It is well-known that many complex physiological adaptations in the thyroid economy occur over a normal pregnancy (5). In summary, the increased concentration of hepatic thyroid-binding globulin, of human chorionic gonadotropin, and the elevation of iodide renal clearance, stimulate the maternal thyroid machinery.…”