Aim of study: An analysis of the efficiency of prenatal diagnostic of selected birth defects in the Czech Republic and its dynamics in past 30 years according to birth defect type and prenatal diagnostic methods. Type of study: Retrospective epidemiological analysis of selected birth defects, prenatal diagnostics efficiency. Material and methods: Data from the National Birth Defect Register (Institute for Health Information and Statistics) in the Czech Republic in the 1975 – 2005 period were used along with data on prenatally diagnosed and terminated pregnancies from the same period. Mean prenatal diagnostic efficiency values of selected types of defects were analyzed in 5-year periods and minimal/maximal values were assessed. Results: During 1975 – 2005 period, totally 3 935 209 children were born, out of which 83 970 were with a birth defect. Mean incidence was 213.38 per 10 000 live births (with the highest value of 414.58 in 2003). In 1985 – 2005, 7398 cases of prenatally detected birth defects (resulting in pregnancy terminations) were registered, which made (in relative numbers) a span from 4.9 defects per 10 000 live births in 1985 to 65.2 per 10 000 live births in the year 2005. During this period, an important increase of diagnostics of prenatally detectable defects occurred. Conclusions: The study gives results of relative efficiency of prenatal diagnostics of particular birth defects. The highest efficiency was in anencephaly and encephalocele (100%), the other defects showed the following numbers: spina bifida 81 %, congenital hydrocephalus 67%, omfalocele 67%, gastroschisis 92%, cystic kidney 59%, renal agenesis 50%, diaphragmatic hernia 35% and Down syndrome 74%.

        Key words: birth defect, incidence, prenatal diagnostics, anencephaly, spina bifida, encephalocele, congenital hydrocefalus, omfalocele, gastroschisis, cystic kidney