[TSH-screening program for congenital hypothyroidism. Experiences with early thyrotropin (TSH) screening].

14,919 newborn infants were screened for congenital hypothyroidism within the last 5 years using a sensitive TSH method. 10 infants with congenital hypothyroidism were discovered thus presenting a frequency of 1:4500. Four of these infants showed abnormally high TSH levels and normal thyroxine levels. The determination of TSH in cord blood--or combined with the screening program for phenylketonuria--in eluate of dried filter paper specimens is the most sensitive test for primary hypothyroidism without false negative results and a low false positive recall rate of 0.16%. After initiation of therapy with thyroxine the TSH level falls unless therapy is delayed for longer. In the latter case TSH levels may remain elevated for several months despite therapy with thyroxine. We would suggest to start therapy with triiodothyronine for up to 14 days prior to initiation of the usual thyroxine therapy.