[Prenatal cytogenetic diagnosis using chromosomal preparations of the native biopsy samples of chorionic villi, cultured chorionic cells and amniocytes].

Analysis of the results of prenatal cytogenetic diagnosis carried out in the first and second pregnancy trimesters in more than 300 women permitted comparing the efficacies of two methodologic approaches, diagnostic amniocentesis and chorion sampling , with due consideration for the methodologic errors typical of these methods and of the tested biologic material. Up to 5% of the diagnoses are erroneous if the diagnosis is based on chorion sampling data, whereas in amniocentesis the share of diagnostic errors is lower by an order. The authors have given a theoretical rationale for and tried a methodologic approach, involving the employment of the 'direct' chromosomal preparations from villous chorion biopsy specimens and the so-called 'maintained' cell culture technique, that permits obtaining chromosomal preparations of higher quality and, consequently, helps improve the accuracy of chromosomal diagnosis.