<unk>  is a method used to determine the risk for the fetus being born with certain chromosomal abnormalities, such as Trisomy 21, Trisomy 18 and Trisomy 13. This testing analyzes small DNA fragments that circulate in the blood of a pregnant woman. Unlike most DNA found in the nucleus of a cell, these fragments are not found within the cells, instead they are free-floating, and so are called cell free fetal DNA (cffDNA). These fragments usually contain less than 200 DNA building blocks (base pairs) and arise when cells die, and their contents, including DNA, are released into the bloodstream. cffDNA derives from placental cells and is usually identical to fetal DNA. Analysis of cffDNA from placenta provides the opportunity for early detection of certain chromosomal abnormalities without harming the fetus.
Non invasive prenatal testing
Preimplantation genetic diagnosis
Prenatal testing
Pre-conception counseling
Obstetric ultrasonography
Fertility testing
Chorionic villus sampling
Preimplantation genetic haplotyping