What is the NIP test or NIPT?
This stands for Non Invasive Prenatal test. It analyses cell free DNA in maternal blood and gives a strong indication of whether the baby is at high or low chance of having trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome) or trisomy 13 (Patau syndrome).
- The test identifies 99%, but not all, of the babies with trisomy 21, 98% of babies with trisomy 18 and 90% of babies with trisomy 13.
- If you decide to have the test, we will then draw a small amount of blood like a normal blood test.
When do I expect to get the results?
- The results from the test will generally be available within two weeks and we will notify you as soon as we receive them by phone and email / letter.
- In about 5% of cases the test does not give a result. This is due to technical problems with the analysis of the sample and does not suggest that there is a problem with the baby. If you want you can have the test repeated (at no cost) and there is a 65% chance that the test will give a result.
What would the NIPT test results show?
- If the test shows that there is a high chance that the baby has trisomy 21 or 18 or 13 it does not mean that the baby definitely has one of these conditions. If you want to be certain if the baby has one of these conditions you should have CVS or amnio.
- If the test shows that there is a low chance (less than 1 in 10,000) that the baby has trisomy 21 or 18 or 13 it is unlikely that the baby has one of these conditions.
Do I need to have any other tests?
- The test does not provide information on other rare chromosomal abnormalities. If the scan at 11-13 weeks shows a high nuchal translucency (more than 3.5 mm) or major defects, the chance for some rare chromosomal conditions may be high. In such cases you may choose to have CVS or amnio.
- The test does not provide information on physical defects, such as heart or brain abnormalities and spina bifida, or fetal growth. It is therefore advisable that you still have ultrasound scans at 11-13 weeks and at 20-22 weeks to examine the fetal anatomy and at 30-32 weeks to examine the fetal growth.
What is the cost of the test?
- If your pregnancy is 10 weeks or more you can have a viability scan and NIPT test at a total cost of £420.
- If your pregnancy is 11+4 weeks or more you can have a nuchal scan (11+4 -13+6weeks) either at NHS or a private ultrasound centre.
Who carries out the analysis of your blood for the NIPT test?
We will send your blood sample along with your personal information (including name, date of birth, gestational age) to INVITAE, a US based lab. The laboratory will extract cell-free DNA from your blood and carry out the NIPT test on the cell-free DNA.
