[Data obtained by prenatal diagnosis of maternal age dependence of fetal chromosomal anomalies].

The connection between fetal chromosomal anomalies and advanced maternal age is well established. Theoretical calculations derived from incidence data and the expected ratio of Down's syndrome babies born to mothers between the age of 35-39 and from 40-45 indicate that fetal kariotyping is necessary at the maternal age of 35 or above. Based on 668 prenatal chromosomal studies (both on cultured amniotic cells and direct preparation of the trophoblast obtained by chorionic villus sampling) authors come to the conclusion that all pregnant women above the age of 35 should undergo fetal karyotyping (in order to detect 22% of the conceptuses with a chromosomal defect) since the incidence rate of abnormal fetal karyotype was found 6.08% between 35-39 years, and 8.49% between 40-45 years of maternal age. To achieve this target about 7500 prenatal karyotyping should be performed per year the laboratory and clinical backgrounds of which should be created.