Talk:Fetal Blood Sampling

From Embryology

Ultrasound guided fetal umbilical cord venipuncture

Fetal blood sampling in baboons (Papio spp.): important procedural aspects and literature review. Joy SD, O'Shaughnessy R, Schlabritz-Loutsevitch N, Leland MM, Frost P, Fan-Havard P. J Med Primatol. 2009 Jun;38(3):151-5. Epub 2009 Apr 5. Review. PMID: 19374666

Prenatal diagnosis: update on invasive versus noninvasive fetal diagnostic testing from maternal blood. Geifman-Holtzman O, Ober Berman J. Expert Rev Mol Diagn. 2008 Nov;8(6):727-51. Review. PMID: 18999924

"The modern obstetrics care includes noninvasive prenatal diagnosis testing such as first trimester screening performed between 11 and 14 weeks' gestation and second trimester screening performed between 15 and 20 weeks. In these screening tests, biochemical markers are measured in the maternal blood with or without ultrasound for fetal nuchal translucency with reported accuracy of up to 90%. Invasive procedures, including amniocentesis or chorionic villi sampling, are used to achieve over 99% accuracy. During these procedures direct fetal material is examined and, therefore, these tests are highly accurate with the caveat of a small risk for pregnancy loss. Much research now focuses on other noninvasive highly accurate and risk-free tests that will identify fetal material in the maternal blood. Fetal cells and fetal DNA/RNA provide fetal information but are hard to find in an overwhelming background of maternal cells and in the absence of specific fetal cell markers. The most experience has been accumulated with fetal rhesus and fetal sex determination from maternal blood, with an accuracy of up to 100% by using gene sequences that are absent from maternal blood. Although not clinically applicable yet, fetal cells, fetal DNA/RNA and fetal proteomics in combination with cutting edge technology are described to prenatally diagnose aneuploidies and single-gene disorders."

Noninvasive prenatal diagnosis of fetal chromosomal aneuploidy by massively parallel genomic sequencing of DNA in maternal plasma. Chiu RW, Chan KC, Gao Y, Lau VY, Zheng W, Leung TY, Foo CH, Xie B, Tsui NB, Lun FM, Zee BC, Lau TK, Cantor CR, Lo YM. Proc Natl Acad Sci U S A. 2008 Dec 23;105(51):20458-63. Epub 2008 Dec 10. PMID: 19073917

"Chromosomal aneuploidy is the major reason why couples opt for prenatal diagnosis. Current methods for definitive diagnosis rely on invasive procedures, such as chorionic villus sampling and amniocentesis, and are associated with a risk of fetal miscarriage. Fetal DNA has been found in maternal plasma but exists as a minor fraction among a high background of maternal DNA. Hence, quantitative perturbations caused by an aneuploid chromosome in the fetal genome to the overall representation of sequences from that chromosome in maternal plasma would be small. Even with highly precise single molecule counting methods such as digital PCR, a large number of DNA molecules and hence maternal plasma volume would need to be analyzed to achieve the necessary analytical precision. Here we reasoned that instead of using approaches that target specific gene loci, the use of a locus-independent method would greatly increase the number of target molecules from the aneuploid chromosome that could be analyzed within the same fixed volume of plasma. Hence, we used massively parallel genomic sequencing to quantify maternal plasma DNA sequences for the noninvasive prenatal detection of fetal trisomy 21. Twenty-eight first and second trimester maternal plasma samples were tested. All 14 trisomy 21 fetuses and 14 euploid fetuses were correctly identified. Massively parallel plasma DNA sequencing represents a new approach that is potentially applicable to all pregnancies for the noninvasive prenatal diagnosis of fetal chromosomal aneuploidies."