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Abstract

Trisomy 21 is the most common autosomal chromosome anomaly. Its incidence ranges from 0.3to 3.4 per 1000 births in different parts of the world. In Egypt, the incidence of Down syndrome hasbeen reported to be one per 1000 births. Screening for Down syndrome through differentbiochemical markers is still and will be a better basic tool for detection of Down syndrome insteadof invasive procedures. The aim of the presented study was to evaluate the triple screening test(using AFP, β-HCG and uE3) in prenatal diagnosis of Down syndrome through comparing theresults of the test with the outcome of pregnancy. We compared these results with the results of thedouble test (using AFP and β-HCG) and MSAFP test to evaluate the value of combining β-HCG,alpha-fetoprotein (AFP) and unconjugated estriol with maternal age in this three-analyte maternalserum screening program for Down syndrome. Triple screening test using AFP, HCG and uE3proved to have the upper hand over MSAFP and double test in detection of Down syndrome as it hasthe highest detection rate and lowest false positive rate.