Thyroid function in neonates from goitrous and nongoitrous iodine-sufficient areas.

We compared thyroid function between newborns from goitrous and nongoitrous localities in which iodine intake has been supplemented since 1955. Cord serum samples were analyzed in 185 infants born during a 9-month period (1986-1987) in 2 goitrous and 1 nongoitrous localities of western Colombia. Urinary iodine was determined in all mothers before delivery. No significant differences were found among neonates of the 3 localities (Kruskal-Wallis test) for the various thyroid hormone values, and all values were within the normal range, although there was a trend in distribution of TSH to higher values in both goiter areas. Thyroid autoantibodies (antithyroglobulin and antithyroid microsomal) were negative in all neonates, and iodine intake, as indicated by urinary iodine, was adequate and similar among the mothers of the 3 groups. Those newborn infants with serum TSH values higher than 20 mU/L were reexamined 5-7 months later. At this time, all infants had lower serum TSH values and their serum free T4 index and T3 values were normal. Gestational age, weight, and height at birth were normal and also equal among the neonates in the 3 localities. These results indicate that neonates from goitrous iodine-sufficient areas have thyroid function similar to that of infants born in nongoitrous areas equally supplemented with iodine, and therefore, they are not more at risk to develop congenital hypothyroidism.

Funcion tiroidea en recien nacidos procedentes de areas con adecuado suplemento de yodo / Thyroid function in newborns coming from areas with adequate iodine supplemet

Este es un estudio comparativo del funcionamiento de la glandula tiroides entre recien nacidos de localidades bociosas y no bociosas suplementadas con yodo desde 1955. Durante nueve meses (1986-1987) se analizaron muestras de sangre del cordon umbilical en 185 ninos nacidos dentro de este periodo en localidades vecinas del occidente colombiano, dos bociosas y una no bociosa. Antes del parto se determino yodo urinario en la totalidad de las madres. Entre los recien nacidos de las tres localidadess no se encotraron diferencias significativas (Prueba de Kruskal-Wallis) en los diferentes valores de hormonas tiroideas. Todos estuvieron dentro del rango normal y aunque en ambas localidades bociosas existia una tendencia hacia valores mas altos en la distribucion de THS medida por el metodo sensitivo inmunorrariometrico IRMA (S-TSH), esta no alcanzo a tener significancia estadistica. Los anticuerpos antitiroglobulina (TgAb) y antitiroideos microsomales (TMAb) fueron negativos en todos los recien nacidos y la ingestion de yodo, como lo indicaba el yodo urinario, fue adecuada y similar en las madres de los tres grupos. los recien nacidos con S-TSH mayor de 20mU/L se reexaminaron cinco a siete meses mas tarde. Para ese tiempo la S-TSH habia descendido en todos estos ninos y el indice de T4 libre (FT4I) y la triyodotironina medida por radioinmunoensayo (T3RIA) fueron normales. La edad gestacional , peso y talla al nacer fueron normales y tambien iguales entre los recien nacidos de las tres localidades. Los resultados indican que los recien nacidos en areas no bociosas...