A method of processing first-trimester chorionic villous biopsies for cytogenetic analysis.

Chorionic villous biopsy is emerging as a technique for obtaining fetal cells for prenatal diagnosis in the first trimester of pregnancy. Chromosome analysis has been performed on small villous biopsies using either direct harvests of uncultured cells or after culturing villous tissue. Here, we describe a method where both techniques can be used simultaneously; from a single villous biopsy, GTG-banded chromosomes of improved morphology are obtained from direct preparations and from cultured villous cells.