Prenatal diagnosis of genetic disorders has traditionally relied on invasive procedures such as amniocentesis and chorionic villus sampling (CVS). As these procedures carry a small but significant risk of pregnancy loss, a convenient noninvasive prenatal diagnostic has long been sought. Although fetal cells circulating in the maternal blood have been used for prenatal screening, because of thei...

References 1. Zhang J, Tong KL, Li PK, Chan AY, Yeung CK, Pang CC, et al. Presence of donorand recipient-derived DNA in cell-free urine samples of renal transplantation recipients: urinary DNA chimerism. Clin Chem 1999;45:1741–6. 2. Zhong XY, Hahn D, Troeger C, Klemm A, Stein G, Thomson P, et al. Cell-free DNA in urine: a marker for kidney graft rejection, but not for prenatal diagnosis? Ann N ...

The discovery of cell-free DNA fetal (cff DNA) in maternal plasma during pregnancy provides a novel perspective for the development of non‑invasive prenatal diagnosis (NIPD). Against the background of maternal DNA, the use of the relatively low concentration of cff DNA is limited in NIPD. Therefore, in order to overcome the complication of the background of maternal DNA and expand the scope of ...

Featured Article: Lo YMD, Tein MSC, Lau TK, Haines CJ, Leung TN, Poon PMK, et al. Quantitative analysis of fetal DNA in maternal plasma and serum: implications for noninvasive prenatal diagnosis. Am J Hum Genet 1998;62:768 –75. There has been a multidecade search for noninvasive methods of prenatal diagnosis. In 1997, my group reported the presence of cell-free fetal DNA in maternal plasma and ...

Cell-free DNA testing in maternal blood provides the most effective method of screening for trisomy 21, with a reported detection rate of 99% and a false positive rate of less than 0.1%. After many years of research, this method is now commercially available and is carried out in an increasing number of patients, and there is an expanding number of conditions that can be screened for. However, ...

Cell‑free fetal DNA (cff‑DNA) is a novel promising biomarker that has been applied in various aspects of obstetrical research, notably in prenatal diagnosis and complicated pregnancies. It is easily detected by semi‑quantitative PCR for the SRY target gene. It is well recognized that the levels of circulating cff‑DNA play a role in various complications of pregnancy. In this review, we explore ...

BACKGROUND Increased second-trimester levels of maternal serum HCG in IVF conceptions lead to an increased false-positive rate in Down syndrome screening. Increased levels of cell-free fetal DNA (cffDNA) in maternal plasma have been correlated with increased HCG levels. Our aim was to determine whether cffDNA levels are elevated in IVF pregnancies compared with natural pregnancies. METHODS Si...