Mixed Karyotypes Obtained by Chorionic Villi Analysis: Mosaicism and Maternal Contamination

Abstract

We report here on a series of chromosome analyses of 60 chorionic villi samples. The villi were obtained from chorionic biopsies carried out immediately before termination of pregnancy or from abortions (spontaneous or induced). Chromosome preparations were made after 20 h preincubation according to the direct method of Simoni et al. (1983) and/or after long-term culture. The villi were either mechanically minced (using scalpels) or enzymatically dissociated (using trypsin, dispase, or hyaluronidase and collagenase IV), then transferred to ambitubes (Nunc). The cells were cultivated in Eagle’s minimum essential medium or RPMI 1640 medium supplemented with 20% fetal calf serum and the usual amount of antibiotics. The results are presented in Table 1. A more detailed summary of the six cases with mixed karyotypes is given in Table 2.