[Neonatal screening for congenital hypothyroidism by measuring TSH in dried blood samples. Two years experience in...

Systematic screening for congenital hypothyroidism was started in Lyon in September 1976. This screening was coupled with PKU screening, using the same dried blood samples in filter paper obtained on the 5 th 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 20 to 30 now 40 muUl/ml of serum. A high level of TSH was found in 307 children (0.55 p. 100). 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 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). Despite a short follow-up the psychomotor development of the infants seems to be normal in all cases but one (one athyreosis with a neonatal injury and a malformative syndrome).