Experience with Real Time Ultrasound Directed Transcervical Chorionic Villus Biopsy

Abstract

The introduction of real time ultrasound to transcervical chorionic villus biopsy allowed successful collection from 65% of 107 consecutive studied patients. The collection rate was obtained despite the need for time to develop scanning skills and a limit of only two attempts at biopsy. The quantity in 69% of biopsy samples was· considered sufficient for use in prenatal diagnosis. Biopsy was most successful between 8 and 10 weeks gestation. No amniotic sac was perforated. Bleeding of varying severity associated with 65% of biopsies was not improved despite use of ultrasound. Both linear array or sector scanners were suitable for our purpose. Clarity of the scan picture is affected by many factors. Successful biopsy is not always dependent on visualisation of the placenta or tip of the collecting cannula. Apart from expertise and ultrasound guidance, better design in biopsy implements can improve successful collection to levels acceptable for clinical applications.