[Neonatal screening of congenital hypothyroidism with TSH measurement in dried blood spots on filter paper. A two years experience (author's transl)].

Systematic screening for congenital hypothyroidism was started in Lyon in september 1976. This screening was coupled with PKU, using the same dried blood samples on filter paper obtained on the 5th day of life. TSH levels were determined by radioimmunoassay adapted for dried blood samples (Kit Abbott). In 24 months, 56 176 samples were analyzed. The critical level calling for control was successively raised from from 20 to 30, now 40 microUI/ml of serum. A high level of TSH was found in 307 children (0,55%). Pathological deliveries were found in most of these infants (neonatal injury, cesarean, section forceps or ocytocic perfusion, neonatal icterus) and a second or a third measurement showed normal TSH level. Congenital hypothyroidism, was found detected in 18 infants: 12 ectopic gland, 5 athyreosis and 1 dyshormonogenesis. Treatment was begun at a mean age of 38 days (29 to 50 days).