EXPANDING MULTIPLE MARKER SCREENING FOR DOWNS-SYNDROME TO INCLUDE EDWARDS-SYNDROME

Information on maternal age and maternal serum alpha-fetoprotein, unco njugated oestriol (uE3), and human chorionic gonadotrophin (hCG) level s was used to investigate retrospectively the effect of estimating Edw ard's syndrome risk in women having multi-marker screening for Down's syndrome. The screened population comprised 15 pregnancies affected by Edward's syndrome, 15 with Down's syndrome and 5472 unaffected pregna ncies. The use of all three markers to estimate Edward's syndrome risk would have led to the detection of 10-12 (67-80 per cent) cases with a false-positive rate of 0.3-0.6 per cent depending on the risk cut-of f. A further case would have been detected as a result of screening fo r Down's syndrome alone. Similar results were obtained when the Edward 's syndrome risk was based on uE3 and hCG only. These data suggest tha t extending Down's syndrome screening to include Edward's syndrome ris k will yield a high detection rate with only a small increase in the f alse-positive rate.