Current foetal DNA sampling methods
The risk aspect of these medical procedures lies in the fact that for both amniocentesis and chorionic villus sampling or CVS, a needle needs to be inserted transabdominally into the womb. The procedure requires application of a local form of aneasthetic and an ultrasound. The stress caused by the presence of the needle in the womb, the actual puncture of the amniotic sack or the contact of the needle with the fetus could have serious consequences, including deforming or injuring the baby’s limbs or a spontaneous abortion (miscarriage)
Our non invasive prenatal paternity test distinguishes itself from all other tests in pregnancy for the following reasons:
Our test is non invasive (meaning it has no risk for the foetus or for the mother)
It is quick and straightforward in terms of sampling
It can be done starting at 9 weeks from conception (this means you will be in your 11th week of pregnancy, starting from the first day of your last menstrual period)
Prenatal testing using cell free fetal nucleic acids in maternal blood
Well over a decade ago, a study pioneered a method of analyzing fetal DNA in pregnancy that is 100% risk free, eliminating all risks of harming the baby or of miscarriage. This study enabled the development of the risk free prenatal paternity test we offer today. The test we offer only requires medical blood draws from the expectant mother and mouth swab samples from the alleged father. From this blood sample, we can isolate the unborn baby’s cell free DNA, compare it to the DNA of the alleged father and determine whether the tested male is the biological father or not.
Fetal genetic material in maternal blood
One of the principal methods by which foetal cells find their way into the maternal blood supply is by apoptosis of placental cells; placental cells die, detach from the placental wall and get replaced with new cells. The dead cells get picked up with the circulatory blood supply. Eventually, these cells will get flushed out of the body. Since cells are continuously dying and being replaced, this process continues throughout pregnancy. In fact, the volume of dead placental cells in a maternal blood sample will increase as pregnancy progresses (due to the increase in size of the fetus).
Method of analysis
This test is indeed different to other methods of DNA analysis we offer (for example, standard after birth paternity test, sibling DNA testing and DNA profiling). To analyse the cell free fetal DNA in the maternal blood sample provided, we use what is known as microarray single nucleotide polymorphism technology. The term single nucleotide polymorphisms or SNPs refer to variations in the genetic code (more accurately and scientifically put, in the sequence of nucleotides) between one individual and another. Analysis of single nucleotide polymorphisms enables very accurate discrimination of foetal DNA. We analyze a total of 2,688 of these SNPs.
Accuracy of this test
Our non invasive prenatal paternity test offers you certitude of 99.9% in cases where the tested father is the biological father of the foetus. If he is not the biological father, he will be excluded with a 100% probability. It is, however, extremely important that the ten week time frame has passed before collecting your samples, this would normally mean the volume of fetal DNA is high enough to conclude the test.