Abstract
Down syndrome is the most common syndrome caused by chromosomal aneuploidy. Screening programs in different countries are concentrated on the prenatal diagnosis of this syndrome.
The total incidence (per 10 000) of Down syndrome cases in livebirths decreased from 7.79 in 1994 to 3.5 in 2011. On the other hand the incidence in prenatally diagnosed cases increased from 5,35 in 1994 to 20,24 in 2011.
The percent of elder mothers (35 years and over) increased from 4.36% in 1994 to 17.03% in 2011. The total number of Down syndrome cases is increasing, however the number of cases in livebirths is steadily decreasing.
During the same time period – the 1st trimestry screening became much more important method of prenatal diagnosis of Down syndrome in the Czech Republic. On the other hand, the demographic situation in the Czech Republic is changing rapidly and we can observe expected increase in the incidence of Down syndrome.