As your baby grows, DNA (genetic material) is released from the placenta into your bloodstream. This DNA is free-floating and called cell-free DNA. When we take a sample of your blood, we can find and learn about this cell-free DNA.
Illumiscreen uses advanced technology to analyse placental DNA and count the number of chromosomes present. The screen is then able to determine if your baby has 46 chromosomes, or too many or too few copies of these chromosomes.
Generally, humans have 23 pairs of chromosomes (46 chromosomes in total). Growth and development can be affected when there are more than 46, less than 46, or when some chromosomes have extra or missing pieces. This is called a chromosomal aneuploidy, which can lead to a chromosome related condition.
Down syndrome is likely the most well-known example of a chromosomal aneuploidy, which is caused by an extra copy of chromosome 21. This is known as trisomy 21 – ‘tri’ indicating three copies.
The three most common chromosome conditions seen in pregnancy are Down syndrome, Edwards syndrome and Patau syndrome.