[Current situation of neonatal screening for congenital hypothyroidism: criticisms and perspectives].

Congenital hypothyroidism (CH) is one of the most common treatable causes of mental retardation. Efforts should be done in its early detection and treatment. Delays in diagnosis and treatment will result in impaired neurocognitive outcomes. Neonatal screening changed the natural history of this disease. The cutoff value for TSH is 10 mUI/L. In Brazil, neonatal screening has been done for three decades. Currently, it is performed in all Brazilian States and the Brazilian Federal District. Looking at recent data on the National Program for Neonatal Screening (NPNS) we can see a huge difference in the results among Brazilian States. NPNS involved 81.61% of the newborns. Only in 56.94% of the cases, samples were collected from newborns up to 7 days of life. Mean time of collection to arrival of the specimen in the lab, TSH determination, release of results and summoning the patient are far longer than the ideal times, causing a delay in early treatment to prevent neurological sequelae. Recent studies have suggested that changing TSH cutoff values to 6 mUI/L may reduce false negative results. Strategies should be adopted to achieve the goals established by the NPNS.