NEONATAL SCREENING FOR CONGENITAL HYPOTHYROIDISM IN ESTONIA

Screening for congenital hypothyroidism was carried out by measuring t hyroid stimulating hormone (TSH) on dried blood spots (mean + 2SD cut off value 12 mu U/ml) by fluoroimmunoassay using DELFIA kits. A total of 20 021 infants were screened, and seven cases with congenital hypot hyroidism were detected, giving an incidence of congenital hypothyroid ism of 1:2860 (female:male ratio 6:1). In four of seven infants with c ongenital hypothyroidism (57%) the mother also had thyroid disease, su pporting the importance of genetic factors as a cause of congenital hy pothyroidism. Transient hyperthyrotropinaemia occurred in 654 infants (recall rate 3.3%). There was a significant association of transient h yperthyrotropinaemia only with cardiac failure at birth or caesarean s ection (p<0.01). Family studies showed no predisposition to thyroid di seases associated with a transient increase of TSH.