Impact of lowering TSH cut-off on neonatal screening for congenital hypothyroidism in Minas Gerais, Brazil

A higher incidence of primary congenital hypothyroidism (CH) has been related to in-creased sensitivity in neonatal screening tests. The benefit of treatment in mild cases remains a topic of debate. We evaluated the cost-benefit of reducing the blood-spot TSH cut-off (b-TSH) from 10 (Group 2) to 6 mIU/L (Group 1) in a public neonatal screening program. During the study period, 40% of 123 newborns with CH (n= 162,730; incidence = 1:1,323) had b-TSH between 6 and 10 mIU/L. Group 1 patients had fewer clinical symptoms (p=0.02), lower serum TSH (p