PRENATAL RISK INDEX FOR FETAL DOWN-SYNDRO ME BY SERUM MARKERS

5 years ago, maternal serum markers have been established for individu al risk estimation of fetal Down syndrome. Recently Bent et al. presen ted an arbitrary age-independent risk index. Compared to the commonly applied statistical approach a 20% increase in detection rate was obta ined by using the index (85% versus 65%). We recalculated data from 19 333 prospectively investigated pregnancies without trisomy 21 and 57 p regnancies with fetal Down syndrome using the proposed risk index. At the corresponding false-positive rate (7,9%) the age-independent detec tion rate was only 56%. This result indicates that the sensitivity can not be increased by the Ulm index, when compared to statistical method s of risk estimation.