Experience with neonatal screening for congenital hypothyroidism in Hungary.

The experience obtained in one of two Hungarian screening centers for congenital hypothyroidism (CH) is reported which is based on the examinations of dried blood samples tested with the aid of TSH-RIA developed in this laboratory. During the past six years (1982-88) and CH was diagnosed in 54 cases out of a total of 306,265 newborns (prevalence: 1:5470). The recall rate because of increased TSH values was 0.28-0.29% within the last two years. The triple of this had to repeat for technical reasons (imperfect samples, borderline results). Within the last year the treatment of diagnosed infants with L-thyroxine was started at the average age of 13 days. The history of three missed cases is briefly reported. Four out of 54 patients (7.4%) died in infancy. Since the pituitary sensitivity for TSH suppression by replacement doses of L-thyroxine appeared to be decreased in several cases, the control of free thyroxine levels is preferred to avoid the clinical hypo- or hyperthyroidism. The shortening of the present three days TSH RIA method, the extension of systematic examination of TSH binding antibodies and psychological studies are in progress.