NIPT Testing
IONA NIPT TESTING (NON-INVASIVE PRENATAL TEST)
Screening for congenital conditions such as Down’s syndrome (T21), Edwards syndrome (T18) and Patau’s syndrome (T13) can be such a difficult decision. It is such a personal choice to make and lots of factors have to be taken into consideration when deciding which path to take. This is why I will always take the time to fully discuss your options and pathways before you decide which screening route if any you would like to take.
Having the choice in screening can sometimes help with making some of those difficult decisions. This is why I am now offering NIPT (non-invasive prenatal test). It is something that is not readily available within the NHS and is generally offered once a woman is given a high chance result following the combined test or Quadruple blood screening test. This means that you would not be offered this test until later in your pregnancy.
The combined test combines an ultrasound scan with a blood test. This is generally done when you have your dating scan from any time between 11-15 weeks. It involves a blood test that measures the hormone hCG and PAPP-A and a scan to looks at Nuchal Translucency (NT) (the skin fold at the back of the baby’s neck, where the spine meets the skull). These two results are combined to give a low chance or high chance result. The combined test has a detection rate of 85% and a false positive rate of 5%.
Sometimes the baby can be in a position that is difficult to see this on scan and so if this is the case you will be offered a quadruple test at 14-20 weeks.
The quadruple test is a blood test and can only test for downs syndrome. This test is less accurate than the combined test and will only detect 80% of babies with Down’s syndrome.
This means that you will have to wait until 20 weeks for your anomaly scan to look for physical conditions that might indicate Edwards syndrome or Patau’s syndrome.
As you can imagine for many uncontrollable reasons finding out your risk factor for these conditions can be a lengthy wait and many women find this extremely stressful.
So, what is different about NIPT?
NIPT can be undertaken much earlier than the Combined test and Quadruple test
NIPT is a blood test that can be undertaken from 10 weeks of pregnancy and therefore it is possible to get a result earlier than with the combined test or quadruple test. Please be aware that it is very important that you have had a scan in order to be sure that you are 10 weeks or more and to determine whether you are carrying twins in order to undertake the NIPT test. Results are available between 2-5 working days from the time the laboratory receives your sample
NIPT has a higher accuracy
The overall accuracy detection rating for trisomy conditions Down’s syndrome (T21), Edwards syndrome (T18) and Patau’s syndrome (T13) is 99.8%. and has a much lower overall false-positive incidence of 0.5% as opposed to 5%. This means that fewer pregnant women will undertake invasive follow up procedures such as amniocentesis or CVS, which can be stressful, uncomfortable and carries a small risk of miscarriage.
