The authors present an account on the incidence of birth defects found in infants under 1 year and the prenatal diagnosis of birth defects in the CR in 1998, and compare it briefly with the previous period 1990 - 1997. In the first part are data on the total incidence of birth defects, in the second part the authors compare the incidence of selected types of birth defects in 1998 with mean frequencies in 1961 - 1990. In the third part the authors compare prenatal and early neonatal mortality rates in the CR in 1998 with the period of 1990 - 1997. The final part presents the results of achieved prenatal diagnosis in selected types of birth defects.

        Key words: birth defect, population teratology, incidence, Czech Republic, prenatal diagnosis, secondary