Chorion villus biopsy.

Chorion villus biopsy answers the pressing need for early prenatal diagnosis. The technique is carried out at about 10 weeks gestation and in most instances this tissue is amenable to direct analysis without culture. This technique is particularly suitable for gene probe diagnosis. However, it is now widely offered for cytogenetic diagnosis on the basis of maternal age and some 10 000 patients have been reported to a Central Registry. The procedure-related abortion rate in skilled hands would seem to be about 2-3%, although this is probably lower with the new transabdominal route. Despite the great deal of attention which is focused on this technique, it is still too early to tell whether chorion villus biopsy will replace amniocentesis as the standard method of prenatal diagnosis.