Accuracy of abnormal karyotypes after the analysis of both short‐ and long‐term culture of chorionic villi

Abstract

We report in detail the cytogenetic results of 1838 consecutivechorionic villus samples with the availability of both short-termculture (STC-villi) and long-term culture (LTC-villi) preparations in1561 cases (84.9%). A high degree of laboratory success (99.5%) anddiagnostic accuracy (99.8%) was observed; in four cases of lowmosaicism, all four associated with the final birth of a normal child, asmall risk of uncertainty was accepted. The combined analysis of STC-and LTC-villi reduced follow-up amniocenteses by one-third in comparisonwith the analysis of STC-villi alone. We believe that the desired levelof quality and accuracy of prenatal cytogenetics in chorionic villi canonly be achieved when both STC- and LTC-villi are available. We concludethat CVS might then be the mode of prenatal diagnosis of first choice inpregnancies with a high (cytogenetic) risk. Copyright (C) 2000 JohnWiley & Sons, Ltd.