OBJECTIVE To examine the possible effects of maternal and fetal characteristics on the fetal fraction in maternal plasma cell-free (cf) DNA at 11-13 weeks' gestation and estimate the proportion of pregnancies at high risk of non-invasive prenatal testing (NIPT) failure because the fetal fraction is less than 4%. METHODS In 1949 singleton pregnancies at 11-13 weeks' gestation cf-DNA was extrac...

variations in detection sensitivity and quantification of fetal DNA concentrations were noted among laboratories very familiar with real-time PCR technology (21). Further studies will be needed to clarify this issue in addition to the continued exploration of other strategies for the investigation of complex fetal genetic traits by analysis of maternal plasma. These strategies may include the e...

BACKGROUND Cell-free fetal nucleic acid, believed to be derived from the placenta/trophoblast, is present in the plasma of pregnant women; however, its use for predictive genetic testing has been severely limited because the circulating fetal DNA is present in a small quantity and mixed with a much larger quantity of maternal DNA. Methods for detecting fetal aneuploidy from the cell-free fetal ...

background: discovery of short cell free fetal dna (cffdna) fragments in maternal plasma has created major changes in the field of prenatal diagnosis. the use of cffdna to set up noninvasive prenatal test is limited due to the low concentration of fetal dna in maternal plasma therefore, employing a high efficiency extraction method leads to more accurate results. the aim of this study was to ev...