Bio-Rad offers a quantitative assay for the determination of Thyroid Stimulating Hormone (TSH) in dried neonatal blood spot specimens, intended for newborn screening for Congenital Hypothyroidism (CH). CH is caused by improper thyroid function. Normally, TSH levels surge after birth, triggering a rise in thyroid hormone. In primary CH, the thyroid gland does not respond to TSH stimulation, resulting in diminished thyroid hormone levels and elevated TSH levels. CH can result in growth failure, deafness, neurological abnormalities and mental retardation. Early treatment is critical to prevent permanent mental retardation and cretinism.