ESTIMATING THE SPONTANEOUS LOSS OF DOWN-SYNDROME FETUSES BETWEEN THE TIMES OF CHORIONIC VILLUS SAMPLING, AMNIOCENTESIS AND LIVEBIRTH

Recent publications concerning the prevalence of Down syndrome at time s of chorionic villus sampling (CVS), amniocentesis and livebirth were reviewed with particular interest in estimates of spontaneous loss of Down syndrome fetuses during pregnancy. Data from several studies wer e combined to provide information on 258 206 pregnancies. A logistic r egression was applied to provide new estimates and confidence interval s (CIs) for spontaneous loss rates between the time of CVS and livebir th (estimate=39 per cent: 90 per cent CI 32 to 45 per cent), and the t ime of amniocentesis and livebirth (estimate=12 per cent; 90 per cent CI 5 to 18 per cent). (C) 1998 John Wiley & Sons, Ltd.