The ins and outs of the New Paternity Test during Pregnancy

12 Aug 2017

Paternity testing during pregnancy has finally taken a step ahead.   Only a few years back it was only possible to do through invasive procedures done by the gynaecologist.  The two main invasive procedures were called CVS (Chorionic villus Sampling) and amniocentesis.  Fetal DNA cells would be collected by entering the womb with instrumentation or by using a syringe on the tummy.  In fact the fetal DNA samples that would normally be collected are called the amniotic fluid or the Chorionic Villi.  There was no other way fetal DNA of the unborn child could be collected in order to carry out a paternity test.

These procedures continue to be uncomfortable and could possibly even lead to bleeding or a miscarriage even though they haven’t been improved over the years.  With the giant leap science has now taken in this field one should definitely consider new the non-invasive procedures.

How does the unborn childs DNA end up in the mothers blood?

The baby in the mothers is connected through the placenta.  This connection enables the baby to receive nutrients and oxygen.  The baby’s waste products are also excreted through this connection.  It is therefore accurate to say that Free Cell DNA is released into the mother’s bloodstream approximately around the 9^th and the 10^th week.  This Free Cell DNA release is maximized after 12^th week and reaches the higher volume after the 25^th week.  It has been known for over 30 years that there is presence of the baby’s DNA in the mothers blood but up till now there was no technology that could amplify the DNA and used it any type of relationship testing.   The technique involves identifying genetic variations in between individuals known as SNP or “Single Nucleotide Polymorphisms.”  This makes it possible to use the genetic markers found in DNA fragments.

How do I go about getting a non-invasive pregnancy paternity test done?

The great news about this new procedure is that sample collection is much simpler than in the previous invasive procedures.  The non invasive paternity test whilst pregnant only requires a blood draw from the mother and the alleged father.   This sample collection can be done by any health care professional being either a General Practitioner or a registered nurse.  The sample collection needs to be carried out after the 9^th week of pregnancy.  Some DNA companies advise that it should be done after the 10^th.  This is because the fetal DNA keeps on increasing in quantity within the mother’s blood, especially in after the 12^th and the 25^th week.  This means that there is a higher fraction of fetal DNA (A higher percentage of fetal DNA present).  The procedure involves getting the blood draw done through any medical practitioner of your choice, utilizing the testing kit that is sent to you by the DNA testing company.  The samples would then need to be submitted directly to the testing laboratory.  A good DNA testing company should offer you an organized sample delivery by express courier on a special laboratory account.  This is important because sending blood samples out of the country by yourself could prove be quite a feat.

Non invasive testing can also be used to detect Down syndrome as well as other chromosomal abnormalities. Click here for more about NIPT testing for down’s syndrome.

Can I expect the non invasive test in pregnancy to give me the same accuracy?

The non-invasive paternity during pregnancy works through a different technique than the previous invasive methods.  The SNP method gives the possibility to detect the free Cell DNA in fragments and put together around 317,000 genetic markers of the unborn child’s DNA.  This DNA information is sufficient to confirm paternity.  The test is furthermore strengthened by running a comparison in between what the outcome is for 5000 random non related men in comparison to the actual man tested.  This allows the laboratory to give an outcome that either completely excludes the test man as the biological father or attributes him at 99.9%.

Therefore we can conclude that the non-invasive paternity test is as accurate as any other invasive paternity testing during pregnancy options.