PRENATAL SCREENING IN THE FIRST-TRIMESTER OF PREGNANCY

Prenatal screening for fetal abnormalities is an accepted part of mode rn obstetric management. Improvements on current screening procedures need to address increased diagnostic efficacy and earlier diagnosis. T his study evaluates the diagnostic efficacy of PAPP-A and F beta-hCG i n the detection of first trimester pregnancy abnormalities, including Down syndrome (DS). Of 731 pregnant volunteers: obtained from a mature age population undergoing chorionic villus sampling (CVS), 17 DS and 11 compromised (six numerical (excluding sex chromosome) aneuploidies, five spontaneously failed) pregnancies were detected. Application of an algorithm, which combines PAPP-A and F beta-hCG levels with materna l age, detected 66.6 per cent of DS pregnancies for a five per cent fa lse positive rate. Similarly, for a 1.2 per cent recall rate: 72.7 per cent of compromised pregnancies were detected. This report supports t he notion that prenatal screening at 9-12 weeks of pregnancy is achiev able with PAPP-A and F beta-hCG quantitation. Whereas mid-gestational screening target-led the detection of fetal abnormalities, screening e arlier in pregnancy will detect other pregnancy-related abnormalities, in addition to aneuploidy. (C) 1998 John Wiley & Sons, Ltd.