Frequently Asked Questions
WHAT IS NIPT?
NIPT is a term used in antenatal screening and can be found in a sample of a mother’s blood. It examines DNA in the chromosomes that originate from a baby’s placenta and with today’s technology. It is used to identify whether you are at an increased risk of giving birth to a child with a genetic disorder. There are 2 chromosomes in a set and a person usually has 46 sets of chromosomes. It can detect where there are extra chromosomes Downs Syndrome or only one of a set ie. Turners Syndrome.
WHO ARE TESTS SUITABLE FOR?
The NIPT test is available for women from 9 or 10 weeks of pregnancy
The test is suitable for single and twin pregnancies (including vanishing twin) Please note that for non-identical twin pregnancies the NIPT test will provide the chance of a Trisomy affected pregnancy for the pregnancy and will not be able to provide a twin-specific chance
The test is suitable for Pregnancies achieved by IVF techniques, including gamets donation
The test is suitable for surrogate pregnancies
NIPT involves a quick blood sample from the arm, making it safe and easy for you and your baby. Your sample is then sent to a lab, where a technician will look at the DNA in your blood for signs of genetic abnormalities. Once the result of your test is analysed the laboratory will determine whether you are placed in the LOWER or HIGHER chance category. This will indicate whether diagnostic testing is needed to confirm the result. Result times can vary between 3-14 working days depending on the level and analysis method of the test you choose. ALL results are delivered personally to you by telephone and a laboratory report is provided by email.
WHEN CAN NIPT TESTS BE PERFORMED?
Trimester ONE NIPT test is available from 9 week’s gestation. All other NIPT’s can be performed any time after 10 weeks — this is earlier than any other antenatal screening or diagnostic test.
NHS antenatal screening;
Nuchal translucency scanning: between 11 and 13 weeks
CVS: 10 to 13 weeks
Quad screen: between 14 and 22 weeks
Amniocentesis usually performed between 16 and 18 weeks & sometimes as early as 13 or 14 weeks or as late as 23 or 24 weeks
THE ACCURACY OF NIPT
NIPT tests create less false alarms than standard NHS first-trimester blood screenings (like first-trimester bloodwork or quad screening). Research has shown that NIPT is much more accurate than those same standard screenings in predicting the risk of Down's syndrome. Because of the high rates of false 'positive' from NHS combined screening, many women are often referred to us from our NHS colleagues. Some hospital offer NIPT privately themselves for a similar fee, however they do not include gender determination AND take much longer to report results.
'HIGHER CHANCE' RESULTS
In the event of a high chance NIPT result we make a medical referral to your local fetal medicine team to help decide next steps forward, including whether to have a fully diagnostic test like Chorionic Villus Sampling (CVS) or amniocentesis (“amnio”). Both tests analyze a baby’s own genetic material, collected from the amniotic fluid or placenta to tell with 100 percent certainty whether a baby actually has a chromosome abnormality. However, these tests are invasive, which means they slightly increase the chance of miscarriage approx 1% nationally ie. approximately 2 in every 200 women.
WHO IS NOT SUITABLE FOR NIPT?
NIPT is not suitable if you have cancer or chromosomal abnormalities including Trisomy 13, 18 and 21.
NIPT cannot be performed if you have had an organ transplant or received stem cell therapy or immunotherapy within the last 12 months.
NIPT cannot be performed if you have had a blood transfusion with the last 3 months.
WHAT IS A FAILED RESULT
This means that it has not been possible to produce a result. In a small number of cases it is possible that there is not enough DNA from your baby present in your blood (Fetal Fraction) to produce the result. The laboratory will request a second sample at no additional cost. However, you may be asked to pay for the Phlebotomy appointment.
Please note: A failed test result will only be reported after testing both samples.