Abstract
1. Congenital hypothyroidism (CH) is a relatively frequent endocrine neonatal disease with a prevalence of 1 to 3,000 newborns. It is usually detected by neonatal screening programs through serum determinations of TSH and total T4. 2. The etiology of CO is, usually, subdivided in permanent and transitory conditions. Permanent conditions that will result in CH are: a) agenesia, ectopy and…