Espectro Clínico de los Trastornos Tiroideos en el Embarazo

Dra. Amanda Coto Quirós
Médico y Cirujano, Universidad de Costa Rica
Investigadora Independiente, San José, Costa Rica.

Dr. David Rodríguez Sánchez
Médico y Cirujano, Universidad de Ciencias Médicas
Investigador Independiente, San José, Costa Rica.

Dr. Rolando Hernández Gaitán
Médico y Cirujano, Universidad de Costa Rica
Investigador Independiente, San José, Costa Rica.

Dra. María Paula Pacheco Salas
Médico y Cirujano, Universidad de Costa Rica
Investigadora Independiente, San José, Costa Rica.

Resumen

Los tratarnos tiroideos son una de las patologías endocrinológicas más frecuentes en el embarazo. Las formas subclínicas son más frecuentes que el hipotiroidismo y el hipertiroidismo clínico. La tiroides sufre distintos cambios fisiológicos durante el embarazo, como la estimulación de los receptores de la hormona estimulante de la tiroides (TSH) por parte de la gonadotropina coriónica humana (hCG), y el aumento de la globulina fijadora de tiroxina (TBG); razones por lo cual ocurre una disminución de los niveles de TSH, y un incremento de los niveles totales de hormonas tiroideas, más no de los niveles libres de las mismas.

Los rangos de normalidad de TSH durante el embarazo, deberían idealmente ser definidos en cada contexto geográfico y ser específicos de cada población y trimestre de embarazo. No obstante, cuando esto no sea posible, se recomienda utilizar un límite superior de 2.5 mIU/L en el primer trimestre de embarazo, y de 3.0 mIU/L en el segundo y tercer trimestre de embarazo. Las formas clínicas de hipertiroidismo e hipotiroidismo, cuya etiología más frecuente son la enfermedad de Graves y la tiroiditis de Hashimoto, respectivamente; están asociadas a múltiples resultados adversos maternos, fetales y neonatales, por lo cual es preciso un adecuado y oportuno diagnóstico y tratamiento para garantizar el bienestar de la unidad materno-fetal. En las formas subclínicas de hipertiroidismo e hipotiroidismo, no hay evidencia científica contundente en la actualidad que las relacione con resultados adversos materno-fetales, por lo cual, no precisan de tratamiento médico.

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Palabras claves

Embarazo, hipertiroidismo, hipotiroidismo, trastornos tiroideos.

Abstract

Thyroid disorders are one of the most frequent endocrinological pathologies in pregnancy. The subclinical forms are more frequent than clinical hypothyroidism and hyperthyroidism. The thyroid gland undergoes different physiological changes during pregnancy, for example, stimulation of thyroid stimulating hormone (TSH) receptors by human chorionic gonadotropin (hCG), and increased thyroxine-binding globulin (TBG); reasons for which there is a decrease in TSH levels, and an increase in total levels of thyroid hormones, but not in their free levels.

The normal ranges of TSH during pregnancy, should ideally be defined in each geographical context, and be population and trimester-specific. Nevertheless, when this is not feasible, it is recommended to use an upper limit of 2.5 mIU/L in the first trimester of pregnancy, and 3.0 mIU/L in the second and third trimesters of pregnancy. The clinical forms of hyperthyroidism and hypothyroidism, which most frequent etiology is Graves' disease and Hashimoto's thyroiditis, respectively; are in fact associated with multiple adverse maternal, fetal, and neonatal outcomes, whereby, an adequate and prompt diagnosis and treatment is required to ensure the well-being of the maternal-fetal unit. In the subclinical forms of hyperthyroidism and hypothyroidism, there is currently no conclusive scientific evidence that associates them with adverse maternal-fetal outcomes, therefore, do not require medical treatment.

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Keywords

Pregnancy, hyperthyroidism, hypothyroidism, thyroid disorders.

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