About the NIPT Test
What is NIPT?
- Non-Invasive Prenatal Testing (NIPT) is a screening test that examines small fragments of DNA (cell free DNA (cfDNA) which are released from the placenta. This is isolated from the mother’s blood and can be tested to determine if there is a chance that that the baby is affected by Down’s, Edwards’ or Patau’s Syndromes.
What will NIPT detect?
- The NIPT test is a targeted tested which will identify if the baby has a chance of being affected by Trisomy 21 (Down’s Syndrome), Trisomy 18 (Edwards’ Syndrome) and Trisomy 13 (Patau’s Syndrome).
- The Vanadis NIPT test offered by Nottingham University Hospitals can also determine the fetal sex if requested.
Why have NIPT?
- Currently, all pregnant women are able to have a combined serum screening test which consists of a blood test and an ultrasound scan. This test is less sensitive than NIPT (86% detection rate for Down’s Syndrome and 80% detection for Edwards’ and Patau’s Syndromes).
- NIPT is a more accurate test as it is >99% sensitive for Down’s and Patau’s Syndromes and 91.7% sensitive for Edwards’ Syndrome
Who can have the NIPT test?
- The NIPT test is available from 10 weeks of pregnancy
- NIPT has been added to the NHS screening pathway for Down’s syndrome, Edwards’ Syndrome and Patau’s syndrome and will be offered at no additional cost following a higher chance result (between 1 in 2 and 1 in 150) from the combined (First Trimester) or quadruple (Second Trimester) test
- The Nottingham NIPT laboratory provides a private NIPT test
- The test is suitable for single and twin pregnancies (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 IVF pregnancies (including donor egg pregnancies)
- The test is suitable for surrogate pregnancies
Who cannot have the NIPT test?
- The NIPT test is not suitable if you have cancer or chromosomal abnormalities including Trisomy 13, 18 and 21
- NIPT cannot be performed in multiple pregnancies greater than twins
- 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
How accurate is the Vanadis NIPT test for Trisomy Screening?
a = based 747 patient samples
b = based on 1035 patient samples
Sensitivity - The ability of the Vanadis NIPT test to identify the condition in pregnancies affected by the condition
Specificity - The ability of the Vanadis NIPT test to correctly identify pregnancies not affected by the condition
PPV - The number of truly positive/affected pregnancies that were reported as positive by the Vanadis NIPT test
NPV - The number of truly negative/unaffected pregnancies that were reported as negative by the Vanadis NIPT test
How accurate is the Vanadis NIPT test for Fetal Sex Determination?
- The Vanadis NIPT test can determine the sex of your baby with 99.6% sensitivity
- If fetal sex determination is required please ensure that this is clearly requested on the request form by ticking the appropriate box in Section 4 of the request form which you can download below:
- Nottingham NIPT Request Form_Version 2.ppt[ppt] 951KB
- Please note that as fetal sex determination is not a medical test it does not meet the definition of an in vitro diagnostic device
How are the results of the Vanadis NIPT test reported?
This means that it is very unlikely that your baby is affected by Down’s, Edwards’ or Patau’s Syndromes
This means that there is an increased chance that your baby is affected by Down’s, Edwards’ or Patau’s Syndromes. All increased chance results should be confirmed by an invasive diagnostic test which could be chorionic villus sampling (CVS) or amniocentesis. Confirmation is required in all increased chance cases as in a very small number of cases the DNA from the placenta may not represent the DNA of your baby
This means that a result has not been able to be produced. In a small number of cases it is possible that there is not enough baby’s DNA in your blood to produce a result.
(Two blood samples will be collected and if the first test fails the second sample will be tested at no additional cost. A failed test result will only be reported after testing of both samples)
This means that the result is not clear and a result cannot be produced.