Frequently Asked Questions (FAQs)
What is the difference between the NHS screen and the NIPT screen?
The NHS screening programme offers a First Trimester (Combined Test) screen or Second Trimester screen. The First Trimester Screen comprises of a blood test to measure biochemical markers, the results of which are combined with the measurements from an antenatal scan to generate a screening chance for Down’s, Edwards’ or Patau’s Syndromes. The Second Trimester Screen comprises of a blood test to measure biochemical markers to generate a screening chance for Down’s Syndrome. The First Trimester screening test has a detection rates of 86% for Down’s Syndrome and 80% for Edwards’ and Patau’s Syndromes. The Second Trimester Screen has a detection rate of 80%.
NIPT is a more accurate test as it analyses the DNA of your baby and has a detection rate of >99% for Down’s Syndrome and Patau’s Syndrome and >91% for Edward’s Syndrome.
Should I have NHS screening and NIPT screening?
It is not recommended to have both NHS and NIPT screening. The NIPT screening test is more accurate and may produce different results from the NHS screen, causing unnecessary concern.
When can I have the NIPT test?
The NIPT test is available for all women from 10 weeks of pregnancy
How long will it take to get the NIPT test result back?
The laboratory will post the NIPT Testing Kit the next working day following receipt of the request and payment. Test results are typically available within 5-10 working days of sample receipt.
Reports are issued by the laboratory and sent electronically upon provision of an E-mail address and paper copies are also sent by First Class Post using the postal address provided on the request form. Additional reports can be sent directly to midwives/clinical professionals upon provision of full postal addresses.
Is NIPT suitable for twin pregnancies?
NIPT is suitable for identical and non-identical twin pregnancies.
In cases of non-identical twin pregnancies the NIPT screen will provide a screening result for the pregnancy and not a foetus-specific screening result.
Sex determination for non-identical twin pregnancies will only be able to state if a male foetus is present and cannot distinguish between a male/male or male/female twin pregnancy. If both foetuses are female this can be determined.
Is NIPT suitable for IVF Pregnancies?
NIPT is suitable for IVF pregnancies (including donor egg pregnancies)
Will the NIPT test always produce a result?
NIPT will not always produce a conclusive result. In very small numbers of cases there may be insufficient amounts of fetal DNA for analysis resulting in inconclusive results. If the reason is due to a laboratory issue, a repeat NIPT test will be offered at no additional cost.
What happens if NIPT does not produce a result?
For each NIPT test the laboratory requires two 10ml blood samples. If the NIPT test fails to produce a result for the first sample the second sample will be tested at no additional cost. If both samples fail to produce a result a repeat NIPT test can be booked.
What should I do if the NIPT test shows an increased chance of Down’s, Edwards’ or Patau’s Syndrome?
NIPT is a screening test and is not a diagnostic test. In a small number of cases the fetal DNA released from the placenta will not be identical to the DNA of the fetus (Confined Placental Mosaicism) and so will produce incorrect results. All NIPT results indicating an increased chance of Down’s, Edwards’ or Patau’s Syndromes should therefore be confirmed using an invasive diagnostic test such as chorionic villous sampling (CVS) or amniocentesis. NIPT results and further testing should be discussed with your midwife or healthcare professional.
Sources for further information
Antenatal Results and Choices (ARC):
National charity offering non-directive information and support to women before, during and after antenatal screening.
(Open Monday to Friday 10am – 5pm)
Down’s Syndrome Association
Helpline: 0333 1212 300
(Open Monday to Friday 10am – 4pm)
Support Organisation for Trisomy 13/18 (SOFT)