Direct-vision chorionic villi biopsy for prenatal diagnosis in the first trimester.

A technique for chorionic biopsy under direct vision has been developed. It involves the transcervical insertion of a fetoscope into the extraamniotic space during continuous saline infusion. With this technique, not only is contamination with maternal tissue easily avoided, but it is even possible to select by direct vision just those villi considered most suitable for cultivation in vitro--i.e., villi rich in blood vessels and with an abundance of surface buds. As of November 1983 the technique had been used for diagnosis in 21 cases. In 19 pregnancies allowed to continue after sampling there was one fetal loss, and one woman gave birth to a healthy infant in the 39th week.