Studies on congenital hypothyroidism and results of three and half years of compulsory screening program in Slovak Socialist Republic.

Abstract

In the introduction the results of previous retrospective study (1975-79) including 312,259 newborns and of preliminary screening program including 31,780 newborns are briefly summarized. After January 1st, 1985 a compulsory screening of congenital hypothyroidism (CH) was started in the whole territory of Slovakia using the estimation of thyroxine in dry blood spot obtained from a heel prick on 5th day after birth. In suspected cases a complete clinical and laboratory examination was made including TSH estimation by RIA and after January 1st, 1988 by IRMA. The organization of screening program is described in detail. During three and half year period 286,469 newborns were examined which represented almost 100 percent of all newborns. A total of 44 cases of CH was found out of them 13 cases of athyreosis, 3 cases of ectopic thyroid and 28 cases of dyshormonogenesis (among them 5 cases with goiter and 23 cases without goiter). The average incidence of CH was 1:6874. Until January 1st, 1988 (when only T4 estimation was used as a first step) the recall rate was 2.32% and the treatment was started before 25th day after birth, while after the use of TSH by IRMA from dry blood spot in suspected cases (i.e. after January 1st, 1988) the recall rate decreased to 0.82% and the treatment was started before 14th day of life. In addition, the data on 39 cases of TBG deficiency and on regional differences in their incidence are reported. Some remarkable differences in the incidence of total CH and of its individual variants between West, Central and East Slovakia with different historical, cultural, economical and genetical background as well as in some ethnic groups (Gypsies) are also presented.