There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Congenital hypothyroidism (CH) is the most frequent congenital endocrine disorder. The diagnosis in industrialized countries is usually made with population-based newborn screening that measures thyroid-stimulating hormone (TSH) or TSH and total thyroxine (T(4)) in dried blood spots in the first 3 days of life. In newborns with a screening result suspicious for hypothyroidism, the diagnosis of primary CH is confirmed when serum TSH levels are above and T(4) (free T(4)) levels are below the age-related reference ranges. Hypothalamic-pituitary hypothyroidism is more difficult to diagnose. Most infants with this diagnosis are missed in screening programs unless T(4) (free T(4))/TSH or TSH/T(4)/thyroxine binding globulin is simultaneously measured. If hypothyroidism is confirmed by laboratory analysis, imaging studies should be performed immediately; however, it is not acceptable to delay hormone replacement therapy if imaging studies are not readily available. The goal of treatment of CH is to avoid disturbed mental development, and initial treatment can be adjusted to physiological conditions. To match the higher thyroid hormone concentrations in the first weeks of life, substitution with l-thyroxine should aim to achieve serum T(4)/free T(4) levels in the upper half of the normal age-related reference range. Some newborns and infants will have persistently high TSH levels despite normalized T(4)/free T(4) serum concentrations. Copyright (c) 2007 S. Karger AG, Basel.

Related collections

Most cited references 22

Record: found
Abstract: found
Article: not found

Neurodevelopmental outcomes in congenital hypothyroidism: comparison of initial T4 dose and time to reach target T4 and TSH.

Jennifer A. Downs, S LaFranchi, Maria Blasco … (2005)

To compare neurodevelopmental outcomes in severe and moderate congenital hypothyroidism (CH) among 3 different initial L-thyroxine doses and to examine the effect of the time to thyroid function normalization on neurodevelopmental outcomes. Neurodevelopmental assessments of 31 subjects included the Mullen Scales of Early Learning, Wechsler Preschool and Primary Scale of Intelligence-Revised, Wechsler Intelligence Scale for Children, Wide-Range Achievement Test, and Child Behavioral Checklist. Subjects started on higher initial L-thyroxine doses (50 mug) had full-scale IQ scores 11 points higher than those started on lower (37.5 mug) initial doses. However, verbal IQ, performance IQ, and achievement scores did not differ among the 3 treatment cohorts. Subjects with moderate CH had higher full-scale IQ scores than subjects with severe CH, regardless of the initial treatment dose. Subjects who took longer than 2 weeks to normalize thyroid function had significantly lower cognitive, attention, and achievement scores than those who achieved normal thyroid function at 1 or 2 weeks of therapy. Initial L-thyroxine dose and faster time to normalization of thyroid function are important to optimal neurodevelopmental outcome. In severe CH, it is important to choose an initial dose at the higher end of the recommended range to achieve these goals.

0 comments Cited 42 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Influence of timing and dose of thyroid hormone replacement on mental, psychomotor, and behavioral development in children with congenital hypothyroidism.

Jacoba J Bongers-Schokking, Sabine de Muinck Keizer-Schrama (2005)

To evaluate the influence of initial and postinitial treatment factors on cognitive, psychomotor, and psychological outcome in schoolchildren with congenital hypothyroidism (CH). We studied 45 patients (19 with severe CH and 26 with mild CH) and 37 control children by correlating initial and postinitial treatment factors (free thyroxine and thyroid-stimulating hormone [TSH] concentrations, and the percentage of overtreatment and undertreatment periods) with the results of neuropsychological tests and behavior (as reported on the Teacher Report Form [TRF]). The global IQ of the children with CH was comparable to that of the controls; visuomotor and verbal scores were lower, and total TRF scores were higher. Ethnic group, previous development, and overtreatment predicted IQ and verbal scores, with higher scores seen for the overtreated patients than for the control children and those patients who had not been overtreated. As initial treatment was less satisfactory, total TRF scores were higher. Our study suggests that initial and postinitial suboptimal treatment of CH leads to abnormalities in IQ and specific fields. Overtreatment may advance cognitive development in 5-1/2- to 7-year-olds. Suboptimal initial treatment may lead to behavioral problems. We recommend that TSH concentrations be maintained within the normal range in patients with CH.