Tratamiento del hipotiroidismo subclínico en gestantes con una dosis fija diaria de 75 µg de tiroxina / Treatment of subclinical hypothyroidism in pregnancy using fixed thyroxine daily doses of 75 microgram

ANTECEDENTES Y OBJETIVOS: Los métodos habituales de cálculo de la dosis inicial de tiroxina en el tratamiento de gestantes hipotiroideas usan el peso de las pacientes (1 microgramo/kg/día) o la concentración plasmática de TSH. Este estudio analiza la idoneidad de tratar a estas mujeres con una dosis fija de 75 microgramo/día de la hormona. PACIENTES Y MÉTODOS: Se seleccionaron mediante un muestreo consecutivo a todas aquellas mujeres diagnosticadas de gestación en el área sanitaria de Vigo entre enero y agosto de 2012, sin antecedentes de tiroidopatía y con una concentración de TSH superior a 4,5 mUI/ml y T4L normal. Las 116 gestantes de la muestra resultante recibieron tratamiento con 75 microgramo/día de tiroxina, y se les hizo un análisis a los 2, 4 y 6 meses tras la instauración del tratamiento, modificándose la dosis de la hormona si la concentración de TSH era inferior a 0,3 o superior a 4,5 mUI/ml. RESULTADOS: Una de las pacientes tuvo, en un análisis, una concentración de TSH inferior a 0,3 mUI/ml; el descenso de la dosis de tiroxina a 50 microgramo/día permitió mantener dicha concentración en el rango deseado hasta el parto. Seis tuvieron en un análisis una concentración de TSH superior a 4,5 mUI/ml; en todas ellas el aumento de la dosis de tiroxina a 100 microgramo/día permitió mantener dicha concentración en el rango deseado hasta el parto. CONCLUSIONES: Una dosis de tiroxina 75 microgramo/día permitió conseguir los objetivos de concentración de TSH de nuestro estudio en la mayoría de las gestantes con hipotiroidismo subclínico, independientemente de su peso y de su concentración inicial de TSH

BACKGROUND AND OBJECTIVES: Treatment of hypothyroid pregnant women is usually calculated based on weight (1 microgram/kg/day) and TSH levels. This study assessed the usefulness of treating these women with a fixed dose of 75 microgram/day. PATIENTS AND METHODS: All women with pregnancy diagnosed from January to August 2012 in the Vigo Health Area (Spain) without previous diagnosis of thyroid disease or thyroxine treatment and with TSH levels over 4.5 mUI/mL were enrolled by consecutive sampling. All 116 women in the sample were treated with a fixed daily dose of thyroxine 75 microgram-thyroxine levels were measured at two, four, and six months, and thyroxine dose was modified if TSH level was lower than 0.3 or higher than 4.5 mUI/mL. RESULTS: A woman had a TSH level less than 0.3 mUI/mL in a test; reduction of thyroxine dose to 50 microgram/day allowed for maintaining TSH level within the desired range until delivery. Six women had TSH levels over 4.5 mUI/mL in one test; in all of them, increase in thyroxine dose to 100 microgram/day allowed for maintaining the level within the desired range until delivery. CONCLUSIONS: Fixed daily doses of thyroxine 75 microgram allowed for achieving goal TSH levels in most of our pregnant women with subclinical hypothyroidism, irrespective of their weight and baseline TSH level

Treatment of subclinical hypothyroidism in pregnancy using fixed thyroxine daily doses of 75 µg.

BACKGROUND AND OBJECTIVES: Treatment of hypothyroid pregnant women is usually calculated based on weight (1 µg/kg/day) and TSH levels. This study assessed the usefulness of treating these women with a fixed dose of 75 µg/day. PATIENTS AND METHODS: All women with pregnancy diagnosed from January to August 2012 in the Vigo Health Area (Spain) without previous diagnosis of thyroid disease or thyroxine treatment and with TSH levels over 4,5 mUI/ml were enrolled by consecutive sampling. All 116 women in the sample were treated with a fixed daily dose of thyroxine 75 µg-thyroxine levels were measured at two, four, and six months, and thyroxine dose was modified if TSH level was lower than 0.3 or higher than 4.5 mUI/ml. RESULTS: A woman had a TSH level less than 0.3 mUI/ml in a test; reduction of thyroxine dose to 50 µg/day allowed for maintaining TSH level within the desired range until delivery. Six women had TSH levels over 4.5 mUI/ml in one test; in all of them, increase in thyroxine dose to 100 µg/day allowed for maintaining the level within the desired range until delivery. CONCLUSIONS: Fixed daily doses of thyroxine 75 µg allowed for achieving goal TSH levels in most of our pregnant women with subclinical hypothyroidism, irrespective of their weight and baseline TSH level.