The kinetics and structure of cell-free fetal DNA in maternal plasma is currently under investigation. Plasma fetal DNA seems quite stable albeit cleared rapidly following birth, suggesting continuous fetal DNA release into the maternal circulation during pregnancy. However, to understand better the kinetics of circulating DNA, studies to determine the biological (structural) form in which feta...

BACKGROUND Detection of circulating cell-free fetal nucleic acids in maternal plasma has been used in noninvasive prenatal diagnostics. Most applications rely on the qualitative detection of fetal nucleic acids to determine the genetic makeup of the fetus. This method leads to an analytic dilemma, because test results from samples that do not contain fetal DNA or are contaminated with maternal ...

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 cell-free fetal DNA (cffDNA) in maternal blood in 1997 by Lo et al. has opened the possibility of a noninvasive prenatal test (NIPT). Currently, it is employed in the analysis of aneuploidies and fetal sex determination. Massive parallel sequencing (MPS) detects the origin of each amplified sequence, and analyses over-representation of sequences or any decrease in the fe...