Prevention of intellectual disability through screening for congenital hypothyroidism: how much and at what level?

Abstract

Although the prevalence of overt disability among children with CHT in the absence of screening may be less than previously estimated, the preventable burden of intellectual disability due to CHT is substantial and justifies newborn screening. However, changes in existing newborn screening protocols to capture more cases are unlikely to prevent overt cases of disability and should therefore be justified instead by the documentation of other benefits of early detection.

Hipotiroidismo congénito, la primera causa de retraso mental prevenible: un desafío para la medicina preventiva

“…El manejo farmacológico y clínico permite mejorar el IQ rápidamente en comparación con los niños que no han recibido tratamiento, incluso aquellos que han sido tratados podrían alcanzar un crecimiento, desarrollo y peso normal para su edad 45 . Además, se ha informado mejora en el estado de ánimo y la función neuropsicológica en pacientes que han sido tratados con una combinación de hormonal T4 y T3 49 ; y mejora en los cambios del desarrollo psicomotor y del lenguaje con el empleo oportuno y temprano de levotiroxina 46,48 . Dentro de las consecuencias negativas del tratamiento por ejemplo podemos encontrar variaciones en el peso que aún no se han correlacionado con niveles hormonales de THS; y compromiso de la inteligencia, donde se evidencian disminuciones del IQ, de 5 a 10 puntos 47 .…”

Decision analysis, economic evaluation, and newborn screening: challenges and opportunities

“…[29][30][31] For these disorders, using data on the severity of outcomes among clinically identified cases to project outcomes in screened cohorts in the absence of screening will overstate the magnitude of morbidity and disability prevented by screening. 32 An appropriate model design for this situation would allow for differing levels of severity in screened and clinically identified cohorts. On the other hand, cases of sudden death due to a disorder, such as congenital adrenal hyperplasia (CAH) or MCAD deficiency, are likely to be missed in the absence of screening.…”

Congenital Hypothyroidism due to Thyroid Dysgenesis: From Epidemiology to Molecular Mechanisms

“…While screening for CH is an unqualified public-health success 19 , a number of controversies mark the almost four decades since it was first implemented. All these controversies have www.intechopen.com three points in common: (a) the biochemical identification of CH and the lack of agreement on the cutoffs used to detect CH 16 , (b) whether there is a correlation between neonatal TSH and T 4 values and later mental development 20,21 , and (c) the fact that CH encompasses a variety of different thyroid etiologies (dysgenesis, dyshormogenesis with goiter, normal-size gland in situ) 12 .…”

“…Before biochemical screening of newborn infants for hypothyroidism was introduced, the mean IQ of children with congenital hypothyroidism was 85 19 , mainly because less than 20% of affected infants were diagnosed within three months after birth; even those with a normal IQ had deficits in fine motor control and learning disabilities 47 . When biochemical screening was implemented, it was rapidly shown that most infants with hypothyroidism treated soon after birth have normal psychomotor development 48 .…”