BACKGROUND: Second-trimester cell-free fetal DNA (studied only in pregnancies with male fetuses) is higher in maternal serum samples from women carrying Down syndrome fetuses than in unaffected pregnancies. In this study we evaluated the potential performance of fetal DNA as a screening marker for Down syndrome. METHODS: Data on maternal serum fetal DNA concentrations and the corresponding concentrations of the quadruple serum markers were available from 15 Down syndrome cases, each matched for gestational age and length of freezer storage, with 5 control samples. Analyte values were expressed as multiple(s) of the control or population median. Screening performance of fetal DNA, both alone and when added to estimates of quadruple marker performance, was determined after modeling using univariate and multivariate gaussian distribution analysis. RESULTS: The median fetal DNA concentration in Down syndrome cases was 1.7 times higher than in controls. In univariate analysis, fetal DNA gave a 21% detection rate at a 5% false-positive rate. When added to quadruple marker screening, fetal DNA increased the estimated detection rate from 81% to 86% at a 5% false-positive rate. CONCLUSIONS: Cell-free fetal DNA, measured in maternal serum, can modestly increase screening performance above what is currently available in the second trimester. If and when maternal serum fetal DNA can be measured in pregnancies with both male and female fetuses, the utility and cost-effectiveness of adding it as a Down syndrome screening marker should be assessed.
BACKGROUND: Second-trimester cell-free fetal DNA (studied only in pregnancies with male fetuses) is higher in maternal serum samples from women carrying Down syndrome fetuses than in unaffected pregnancies. In this study we evaluated the potential performance of fetal DNA as a screening marker for Down syndrome. METHODS: Data on maternal serum fetal DNA concentrations and the corresponding concentrations of the quadruple serum markers were available from 15 Down syndrome cases, each matched for gestational age and length of freezer storage, with 5 control samples. Analyte values were expressed as multiple(s) of the control or population median. Screening performance of fetal DNA, both alone and when added to estimates of quadruple marker performance, was determined after modeling using univariate and multivariate gaussian distribution analysis. RESULTS: The median fetal DNA concentration in Down syndrome cases was 1.7 times higher than in controls. In univariate analysis, fetal DNA gave a 21% detection rate at a 5% false-positive rate. When added to quadruple marker screening, fetal DNA increased the estimated detection rate from 81% to 86% at a 5% false-positive rate. CONCLUSIONS: Cell-free fetal DNA, measured in maternal serum, can modestly increase screening performance above what is currently available in the second trimester. If and when maternal serum fetal DNA can be measured in pregnancies with both male and female fetuses, the utility and cost-effectiveness of adding it as a Down syndrome screening marker should be assessed.
Authors: Ji Hyae Lim; Bom Yi Lee; Jin Woo Kim; You Jung Han; Jin Hoon Chung; Min Hyoung Kim; Dong Wook Kwak; So Yeon Park; Hee Back Choi; Hyun Mee Ryu Journal: J Assist Reprod Genet Date: 2018-02-08 Impact factor: 3.412
Authors: Neeta L Vora; Kirby L Johnson; Geralyn Lambert-Messerlian; Hocine Tighiouart; Inga Peter; Adam C Urato; Diana W Bianchi Journal: Obstet Gynecol Date: 2010-09 Impact factor: 7.661
Authors: Ji Hyae Lim; Shin Young Kim; So Yeon Park; Shin Yeong Lee; Mi Jin Kim; You Jung Han; Si Won Lee; Jin Hoon Chung; Moon Young Kim; Jae Hyug Yang; Hyun Mee Ryu Journal: PLoS One Date: 2011-11-23 Impact factor: 3.240