Women's choices for fetal chromosome analysis.

Five hundred and eighty women aged 35 or more at the expected date of delivery were offered the chance to join the MRC trial comparing CVS and amniocentesis at Queen Charlotte's Hospital. After a 1 h non-directive counselling session, they were asked to choose between having no test, having amniocentesis, or joining the trial in the hopes of having CVS (or in some cases having CVS outside the trial). The majority of women chose to have some test, and CVS was a more popular choice than amniocentesis.