Non-invasive prenatal determination of fetal gender using QF-PCR analysis of cell-free fetal DNA in maternal plasma

Abstract

BackgroundDetection of cell-free fetal DNA (cffDNA) in maternal plasma has given rise to the possibility of new non-invasive approaches for early prenatal diagnoses. We evaluated the feasibility and accuracy of non-invasive fetal gender determination using quantitative fluorescent-polymerase chain reaction (QF-PCR) analysis of circulating cffDNA in the first-trimester maternal plasma. MethodsPlasma samples were prospectively collected from 202 singleton pregnancies at 4 to 13weeks of gestation. Fetal gender was determined by QF-PCR with the sex-determining region Y (SRY) and amelogenin X/Y (AMELX/Y) genes. The result was confirmed by fetal karyotyping or phenotype at birth. ResultsOf the 202 pregnancies, 162 had pregnancy outcomes available and could be included in our evaluation. The accuracies of AMELX/Y, SRY, and combined AMELX/Y+SRY analysis for fetal gender determination were 83.3%, 82.1%, and 97.5%, respectively, compared with those of the invasive approach and the fetal gender outcome at birth (82 males and 80 females). Combined AMELX/Y+SRY analysis had the highest sensitivity (98.8%) for fetal gender determination with a specificity of 96.3%. Moreover, fetal gender detection by the combined AMELX/Y+SRY analysis at 11 to 13weeks of gestation was 100% correct. ConclusionFetal gender determination could be accurately determined from maternal cffDNA in the first-trimester using QF-PCR analysis of combined AMELX/Y+SRY.