Neonatal screening for congenital hypothyroidism

In Austria, neonatal screening for congenital hypothyreosis has been introduced since 1976 as a part of the national screening program for inborn errors of metabolism. Capillary blood spots are collected on filter paper from all newborns on day 3 to 5 and are subsequently investigated with a delayed fluorescence-immunoassay (DELFIA) for the determination of TSH. Since 1992 we have detected 105 patients with congenital hypothyreosis among 365,120 newborns. The recall rate of the primary TSH screening is about 0.35%. Only primary (thyroidal) hypothyreosis, but not secondary and tertiary (pituitary and hypothalamic) types of hypothyreosis are detected by the primary TSH newborn screening. As TSH is physiologically high during the first 2 days of life, the trend to early hospital discharge will result in a significant increase of the recall rate in future.