The syndrome of hypoplasia of the left heart (HLHS) is an inborn heart defect with severe prognosis. In spite of the great development of the child cardiosurgery there is still a high mortality. Prenatal diagnosis of HLHS significantly influences further fate of the fetuses. The incidence and fate of patients with HLHS have not been so far investigated in the area of Moravia and Silesia, since the epidemiological Bohemian Survival Study included only the Czech countries (Bohemia). In the years 2002 and 2003, our workplace which takes care of the Moravia and Silesia region, examined 4,667 fetuses, 108 of them suffering from inborn heart defect. In the same period of time 69,623 newborns were born in this area, 478 of them having inborn heart defect. HLHS occurred in 24 of them, i.e., 5% of all inborn heart defects. In 21 cases (87.5%) the HLHS diagnosis was established before birth, whereas in three of then after birth. HLHS represented 19.5% of all heart defects diagnosed before birth. In 21 HLHS, where the diagnosis was established before birth, the parents decided to end the pregnancy in 17 cases (81%), in four cases they decided the pregnancy to countinue. The authors evaluated the detectable risk factors before birth and established them in 12 fetuses, whereas no risk factor was found in 9 fetuses. The examination of karyotype in HLHS established in prenatal period revealed normal picture in 62% of cases, 9.5% being pathological and 28.5% and it was not determined in 28.5% at all. The occurrence of HLHS in our region proved to be comparable with data in literature. Authors have not been able to find a method other than ultrasonography, which would draw attention to HLHS and this method therefore remains to be the decisive method for prenatal diagnostics of HLHS.

        Key words: syndrome of left heart hypoplasia, prenatal diagnosis, risk factors