First-trimester transcervical chorionic villus sampling by biopsy forceps versus mid-trimester amniocentesis: A randomized controlled trial project

Up to now, no data are available comparing amniocentesis and chorionic villus sampling (CVS) using biopsy forceps. A series of 1313 consecutive women referred to our unit before 12 weeks of pregnancy for fetal cytogenetic analysis because of advanced maternal age, were randomized into CVS with the use of transcervical biopsy forceps or mid-trimester amniocentesis. The diagnostic success rates of the two groups were 98 per cent and 100 per cent, and a second procedure was needed in 4.1 per cent (13/314) and in 0.3 per cent (1/358), respectively. Follow-up was achieved in 98.7 per cent of the pregnancies. Postprocedure spontaneous fetal losses, until the first week after birth, in the 672 pregnancies that completed the trial accounted for 2.2 per cent (7/314) in the CVS group and 2.8 per cent (10/358) in the amniocentesis group. Although the trial was prematurely discontinued, and therefore the sample size was smaller than initially planned, the results indicate that transcervical CVS was as safe as mid-trimester amniocentesis. Copyright (C) 1999 John Wiley & Sons, Ltd.