Evolución del estado de nutrición de yodo en gestantes del area sanitaria de Pamplona / Change over time in the iodine nutritional status of pregnant women from the Pamplona healthcare region

INTRODUCCIÓN: La ingesta adecuada de yodo es esencial durante el embarazo. Sin embargo, una parte de la población gestante de nuestro país persiste en una situación de yododeficiencia. Un estudio previo realizado en embarazadas del área sanitaria de Pamplona mostró una yoduria insuficiente (125 mcg/l) y un bajo consumo de sal yodada. El objetivo del presente trabajo es conocer la ingesta de yodo y analizar la evolución del estado de yodación en gestantes de nuestro medio en los últimos años. MÉTODOS: Estudio observacional de 400 gestantes de primer trimestre sin antecedentes conocidos de enfermedad tiroidea. Se cumplimentó un cuestionario de consumo de yodo. Como marcadores del estado de yodación se analizaron la yoduria en una muestra simple de orina y la tiroglobulina sérica, y se calculó el volumen tiroideo mediante ecografía cervical. RESULTADOS: El 70,5% de las participantes consumía sal yodada (55,3% pregestacional) y el 98,5% suplementos farmacológicos con yodo (dosis 202,6±30,1 mcg/día). La mediana de la yoduria fue 242 mcg/l (138,5-415,5 mcg/l) y de la tiroglobulina 12,3 mcg/l (8,39 mcg/l). El consumo de sal yodada se asoció a mayor yoduria y a un menor volumen tiroideo. No se encontraron diferencias en los parámetros estudiados en función del consumo de lácteos, pescado o huevos. CONCLUSIONES: La ingesta de yodo en gestantes de Pamplona ha aumentado, tanto a expensas del empleo de sal yodada como de la dosis de la suplementación farmacológica. Esto ha permitido alcanzar un estado de yodación adecuado

INTRODUCTION: Adequate iodine intake is essential during pregnancy. A previous study of pregnant women from the Pamplona healthcare region showed mild iodine deficiency (mean urinary iodine level, 125 mcg/L). This study was intended to ascertain the iodine intake of pregnant women in our region and to analyze the change over time in their iodine nutritional status. METHODS: An observational study of 400 women in their first trimester of pregnancy. An iodine intake questionnaire was administered. To assess iodine status, urinary iodine concentration (UIC) was measured in a simple urine sample, and serum thyroglobulin levels were determined. In addition, thyroid volume was measured by cervical ultrasound examination. RESULTS: Iodized salt was used by 70.5% of all participants (55.3% since the pre-gestational period) and 98.5% of them received iodine-containing supplements (mean dose, 202.6±30.1 mcg/day). Mean urinary iodine concentration was 242 mcg/L (138.5-415.5 mcg/L) and the mean serum thyroglobulin level was 12.3 mcg/L (8.3-9 mcg/L). Iodized salt intake was associated with higher UICs and lower thyroid volume. No differences were found in any of the tested parameters regarding the intake of dairy products, fish, or eggs. CONCLUSIONS: Iodine intake by pregnant women in Pamplona has increased due to a greater use of iodized salt and to higher doses of iodine supplements. As a result of this, an adequate iodine status has been achieved in the last decade

Change over time in the iodine nutritional status of pregnant women from the Pamplona healthcare region. / Evolución del estado de nutrición de yodo en gestantes del area sanitaria de Pamplona.

INTRODUCTION: Adequate iodine intake is essential during pregnancy. A previous study of pregnant women from the Pamplona healthcare region showed mild iodine deficiency (mean urinary iodine level, 125 mcg/L). This study was intended to ascertain the iodine intake of pregnant women in our region and to analyze the change over time in their iodine nutritional status. METHODS: An observational study of 400 women in their first trimester of pregnancy. An iodine intake questionnaire was administered. To assess iodine status, urinary iodine concentration (UIC) was measured in a simple urine sample, and serum thyroglobulin levels were determined. In addition, thyroid volume was measured by cervical ultrasound examination. RESULTS: Iodized salt was used by 70.5% of all participants (55.3% since the pre-gestational period) and 98.5% of them received iodine-containing supplements (mean dose, 202.6±30.1 mcg/day). Mean urinary iodine concentration was 242 mcg/L (138.5-415.5 mcg/L) and the mean serum thyroglobulin level was 12.3 mcg/L (8.3-9 mcg/L). Iodized salt intake was associated with higher UICs and lower thyroid volume. No differences were found in any of the tested parameters regarding the intake of dairy products, fish, or eggs. CONCLUSIONS: Iodine intake by pregnant women in Pamplona has increased due to a greater use of iodized salt and to higher doses of iodine supplements. As a result of this, an adequate iodine status has been achieved in the last decade.

Optimización del seguimiento de gestantes con enfermedad tiroidea autoinmune / Optimization of the follow-up of pregnant women with autoimmune thyroid disease

Objetivo: Determinar el riesgo de hipotiroidismo en gestantes con enfermedad tiroidea autoinmune y tirotropina (TSH) < 2,5 mUI/l al inicio del embarazo. Métodos: Estudio prospectivo longitudinal en gestantes de primer trimestre sin antecedentes de patología tiroidea y con TSH en primer trimestre < 2,5 mUI/l. Se determinaron TSH, tiroxina libre (T4l) y anticuerpos antiperoxidasa (TPO) y antitiroglobulina en los 3 trimestres. Se comparó la evolución de la función tiroidea y la aparición de hipotiroidismo gestacional (TSH > 4 mUI/l), entre las gestantes con autoinmunidad positiva y autoinmunidad negativa. Resultados: Se incluyeron 300 gestantes con TSH basal 1,3 ± 0,6 mUI/l (semana gestacional 9). El 17,7% (n = 53) tenían autoinmunidad positiva en el primer trimestre. Los títulos de anticuerpos TPO y antitiroglobulina disminuyeron entre el primer y el tercer trimestre un 76,8% y un 80,7% respectivamente. La evolución de la función tiroidea fue similar en el grupo con autoinmunidad positiva y el grupo con autoinmunidad negativa, y la aparición de hipotiroidismo fue del 1,9% (1/53) y del 2% (5/247) respectivamente. Las gestantes en las que la TSH aumentó por encima de 4 mUI/l (n = 6) tenían cifras superiores de TSH basal en comparación con las que mantuvieron TSH≤4 mUI/l a lo largo del embarazo (1,8 vs. 1,3 mUI/l; p = 0,047). Conclusión: En nuestra población, las mujeres con TSH < 2,5 mUI/l al inicio del embarazo tienen un riesgo mínimo de desarrollar hipotiroidismo durante la gestación, independientemente de la autoinmunidad tiroidea

Objective: To determine the risk of hypothyroidism in pregnant women with autoimmune thyroid disease and thyrotropin (TSH) < 2,5 mIU/l at the beginning of pregnancy. Methods: Prospective longitudinal study of pregnant women with no personal history of thyroid disease, and with TSH < 2.5 mIU/l in the first trimester. TSH, free thyroxine (FT4), anti peroxidase (TPO) and anti thyroglobulin antibodies were measured in the 3 trimesters of pregnancy. We compared thyroid function throughout pregnancy, and the development of gestational hypothyroidism (TSH >4 mIU/l) among pregnant women with positive thyroid autoimmunity and those with negative autoimmunity. Results: We included 300 pregnant women with mean baseline TSH 1.3 ± 0.6 mIU/l (9th gestational week). Positive thyroid autoinmunity was detected in 17.7% of women (n = 53) at the first trimester. Between the first and the third trimesters, TPO and anti thyroglobulin antibodies titers decreased 76.8% and 80.7% respectively. Thyroid function during pregnancy was similar among the group with positive autoimmunity and the group with negative autoimmunity, and the development of hypothyroidism was 1.9% (1/53) and 2% (5/247) respectively. Pregnant women in whom TSH increased above 4 mIU/l (n = 6), had higher baseline TSH levels compared to those who maintained TSH ≤4 mIU/l during pregnancy (1.8 vs. 1.3 mIU/l; p=.047). Conclusion: In our population, women with TSH levels <2.5 mIU/l at the beginning of pregnancy have a minimal risk of developing gestational hypothyroidism regardless of thyroid autoimmunity

Thyroid Function Reference Values in Healthy Iodine-Sufficient Pregnant Women and Influence of Thyroid Nodules on Thyrotropin and Free Thyroxine Values.

BACKGROUND: Thyroid function assessment in pregnancy requires specific reference intervals stratified by gestational age and according to each laboratory method. Thyroid nodules may influence thyroid function in pregnant women. The aims of this study were to define the reference values of thyrotropin (TSH) and free thyroxine (fT4) in the three pregnancy trimesters in iodine-sufficient pregnant women, and to analyze the influence of thyroid nodules on thyroid function during pregnancy. METHODS: This was a prospective, longitudinal study comprising 400 pregnant women with no history of thyroid disease and no medication influencing thyroid function. TSH, fT4, antithyroglobulin, and antithyroid peroxidase antibodies were measured each trimester by chemiluminescent immunoassays. Urinary iodine concentration was measured in the first trimester when a thyroid echography was also performed. Women with multiple gestation pregnancies, positive thyroid autoimmunity, TSH values >5 or <0.1 mIU/L with a simultaneous fT4 level above the general population reference value in the first trimester, or clinically significant thyroid nodules (nodules ≥1 cm and/or multiple nodules) were excluded to establish TSH and fT4 reference values. RESULTS: Reference intervals in the first, second, and third trimesters were 0.13-4.16, 0.31-3.73, and 0.58-4.36 mIU/L, respectively, for TSH, and 0.85-1.24, 0.82-1.20, and 0.67-1.06 ng/dL, respectively, for fT4. The total prevalence of thyroid nodules was 28.8% [95% confidence interval (CI) 24.4-33.5%], and 6.0% of the participants showed clinically significant nodules. Pregnant women with thyroid nodules (n = 115) showed consistently lower TSH values during all pregnancy stages (first trimester: median 1.14 mIU/L [interquartile range (IQR) 0.53-1.75 mIU/L] vs. 1.48 mIU/L [IQR 0.94-2.19 mIU/L], p < 0.001; second trimester: 1.22 mIU/L [IQR 0.66-1.77 mIU/L] vs. 1.45 mIU/L [1.04-2.05 mIU/L], p = 0.001; third trimester: 1.74 mIU/L [IQR 1.08-2.36 mIU/L] vs. 1.93 mIU/L [IQR 1.37-2.58 mIU/L], p = 0.041) and higher fT4 values in the first trimester (M ± SD = 1.08 ± 0.14 ng/dL vs. 1.03 ± 0.12, p < 0.001) compared to those without nodules (n = 285). Both pregnant women with clinically significant thyroid nodules and those with nonsignificant ones had lower TSH values than women without nodules. CONCLUSIONS: TSH/fT4 reference intervals in pregnant women from the authors' geographical area will thyroid dysfunction in pregnancy to be appropriately diagnosed. The prevalence of thyroid nodules is high in iodine-sufficient pregnant women, and is associated with low TSH values across pregnancy.

Optimization of the follow-up of pregnant women with autoimmune thyroid disease. / Optimización del seguimiento de gestantes con enfermedad tiroidea autoinmune.

OBJECTIVE: To determine the risk of hypothyroidism in pregnant women with autoimmune thyroid disease and thyrotropin (TSH) < 2,5 mIU/l at the beginning of pregnancy. METHODS: Prospective longitudinal study of pregnant women with no personal history of thyroid disease, and with TSH < 2.5 mIU/l in the first trimester. TSH, free thyroxine (FT4), anti peroxidase (TPO) and anti thyroglobulin antibodies were measured in the 3 trimesters of pregnancy. We compared thyroid function throughout pregnancy, and the development of gestational hypothyroidism (TSH >4 mIU/l) among pregnant women with positive thyroid autoimmunity and those with negative autoimmunity. RESULTS: We included 300 pregnant women with mean baseline TSH 1.3 ± 0.6 mIU/l (9th gestational week). Positive thyroid autoinmunity was detected in 17.7% of women (n = 53) at the first trimester. Between the first and the third trimesters, TPO and anti thyroglobulin antibodies titers decreased 76.8% and 80.7% respectively. Thyroid function during pregnancy was similar among the group with positive autoimmunity and the group with negative autoimmunity, and the development of hypothyroidism was 1.9% (1/53) and 2% (5/247) respectively. Pregnant women in whom TSH increased above 4 mIU/l (n = 6), had higher baseline TSH levels compared to those who maintained TSH ≤4 mIU/l during pregnancy (1.8 vs. 1.3 mIU/l; p=.047). CONCLUSION: In our population, women with TSH levels <2.5 mIU/l at the beginning of pregnancy have a minimal risk of developing gestational hypothyroidism regardless of thyroid autoimmunity.