background: free fetal dna (ffd) in maternal plasma/serum has increasingly become the source of fetal material for diagnostic purposes in recent years. this source of fetal material can be used for sex determination. rh typing paternally inherited sequences and compound heterozygosity. reports on the lack of consistent pcr amplification of y-chromosome sequences of ffd in maternal plasma/serum ...

cell free dnas (cfdnas) are small fragments of genomic or mitochondrial dna releasing from cells into the blood stream. the presence of cfdna in the human circulatory system has been shown for the first time in 1948 however, the potential clinical applications of cfdna remained unknown until recent progress in detection and quantification of these molecules by sensitive methods. in this paper, ...

Background: It is well documented that fetal DNA can cross the placenta and is present in peripheral maternal blood during pregnancy in human. This fetal DNA also named circulating cell free fetal DNA, has emerged as a valuable source for genetic evaluation. Compared with humans, ovine species have a different structure of placental (synepitheliochorial) with no direct contact between the troph...

Fetal cells, specifically fetal erythroblasts, as well as cell-free fetal DNA are present in the maternal circulation. Both are currently being investigated as a means for the non-invasive risk-free analysis of fetal genetic traits. The origin of this cell-free fetal DNA in the maternal circulation is currently unclear. Since numerous fetal erythroblasts have been demonstrated to exhibit an apo...

Discovery of cell free fetal DNA in 1997 has deeply changed the outlook of prenatal diagnosis approaches as most of the clinically established screening tests are not sensitive/specific enough while the current practical diagnostic tests are also invasive in their nature. The most common prenatal screening test is routinely practiced for the diagnosis of Down syndrome (DS) which includes a 10% ...

Cell-free DNA has emerged as the most reliable, non-invasive prenatal screening tool for fetal aneuploidies. It come to replace previously widely used quadruple screen offered in second trimester of pregnancy. This change comes with improved detection aneuploidy but also presents potential gaps diagnosis including open defects and emerging data on prediction adverse pregnancy outcomes. review a...

background: the discovery of circulating fetal dna in maternal blood led to the discovery of new strategies to perform noninvasive testing for prenatal diagnosis. objective: the purpose of the study was to detect fetal aneuploidy at chromosomes 13, 18, 21, x, and y by analysis of fetal cell-free dna from maternal blood, without endangering pregnancy. materials and methods: this retrospective st...

Both intact fetal cells as well as cell-free fetal DNA are present in the maternal circulation and can be recovered for non-invasive prenatal genetic diagnosis. Although methods for enrichment and isolation of rare intact fetal cells have been challenging, diagnosis of fetal chromosomal aneuploidy including trisomy 21 in first- and second-trimester pregnancies has been achieved with a 50-75% de...

OBJECTIVE To provide an introduction to new technologies involving maternal plasma cell-free fetal DNA for non-invasive prenatal diagnosis and screening in obstetrics. OPTIONS Limited to introductory discussion of maternal plasma cell-free fetal DNA. EVIDENCE MEDLINE was searched to identify publications related to the topic after 1996. This document represents an abstraction of the informa...