What is NIPT?

What is NIPT?

Non-invasive prenatal testing (also called cell free fetal DNA screening) is essentially a blood test taken from the mother to look at the babies DNA to screen for chromosomal and genetic conditions.

Advantages:

• The major advantage of NIPT is that it is the best screening test for chromosomal and genetic conditions.
• No risk of miscarriage.
• You will be seen and counselled by a specialist Consultant in Fetal Medicine.
• The test can be performed from as early as 10 weeks (9 weeks with the Panorama test)
• A very high detection rate and a very low false positive rate (the majority of cases screened for are detected and very few mothers get a high chance result) unlike the standard NHS tests (Combined or Quadruple screening).
• The test works extremely well in all twin pregnancies.
• The results are very clear; you either receive a low chance result or a high chance result.
• In the unlikely scenario that you get a high chance result your consultant will call you personally to discuss the implications and the most suitable next steps for you.
• We are now offering a range of tests including the most extensive NIPT which tests for a wide range of chromosomal and genetic abnormalities (PrenatalSafe 9).

Disadvantages:

• Most tests take about 3-5 working days to provide a result. The Panorama test is sent to the USA, and it takes 10 working days to receive the result.
• In up to 2% of cases we cannot provide a result with the first sample and will ask you to return for a second blood sample at no additional cost. This is usually because there is insufficient fetal DNA in the first sample for accurate evaluation.
• Rarely (less than 1%) the test will not provide a result. If this happens, we will explain the implications and we will refund the cost of the test.
• The test does not work in high order multiple pregnancies (triplets or more)

When can I get the test done?

The vast majority of NIPT tests available are performed from 10+0 weeks. The Panorama test offers testing from 9+0 weeks. It is ideal that you have a scan on the day or at least have had a scan within the last 14 days to confirm the gestational age, to count the number of babies (i.e singleton or multiple pregnancy) and to confirm that the pregnancy is developing normally (we will start to look for major anomalies from 10 weeks).

What happens during my NIPT appointment?

Ultrasound examination:

We will perform an ultrasound examination before taking the blood sample. In most cases this is an abdominal scan (from your abdomen/tummy) but sometimes the views are limited, and we will need to perform a transvaginal scan with your consent.

The reason for the scan is to confirm that the pregnancy is developing normally. Under the rare circumstance that a fetal anomaly is seen on scan, we will explain the findings and make recommendations on available choices. Sometimes NIPT is not the best test in these circumstances (because it is a screening test and not diagnostic), and we will guide you through the best options. The scan will accurately date the pregnancy (NIPT will not work if the blood is taken too early) and allow us to count the number of babies (about 1 in 80 mothers will be surprised to hear that they have more than one baby).

If you have had a scan performed within the last 14 days, we do not have to perform a scan if you wish.

Take a blood sample:

A routine blood sample is taken from your arm – the same as any other blood test.

What does NIPT screen for:

NIPT can screen for a very wide range of chromosomal and genetic conditions.

NIPT is most often used to screen for:

• Down’s syndrome (Trisomy 21)
• Edward’s’ syndrome (Trisomy 18)
• Patau syndrome (Trisomy 13)
• Fetal sex – if requested by the parents

The major advantage of NIPT is the very high detection rate with a very low false positive rate (<0.1%), without any risk of miscarriage. This means that the test will detect the majority of cases of these three common fetal aneuploidies and very few women will be given a high chance result (unlike the traditional Combined or Quadruple test offered in the NHS which has a lower detection and a false positive rate of about 3%.

Performance of NIPT compared to the Combined Test

Which NIPT is more suitable for me?

One of our many strengths is that we are all consultants in Fetal Medicine and have both specialist and detailed knowledge about the tests available. We currently offer the PrenataSafe test, the Illumina test, and the Panorama Test and we are very happy to discuss which test will suit your individual needs.

NIPT options at a glance