At a glance
Looking for a more accurate Down Syndrome test? Want to avoid the risks associated with diagnostic testing? Why not consider a Non-Invasive Prenatal Test?
A screening test for Down Syndrome for later in the second trimester using a blood test.
- 78% detection rate
- No GP referral required
- Non invasive test
- Suitable if you’ve missed the nuchal or integrated test
- Screening performed by a highly qualified sonographer or consultant
- Appointments available at short notice
- Convenient central London location
You will receive
- Results in 4 working days
- Two-page clinical report, plus screening results from laboratory
- Complimentary black & white picture (normally £2.50)
What happens with your results?
We will call you 4 days after your appointment to let you know your results and will send you a report detailing your estimated risk.
What is it?
It’s called the quadruple test because it measures four substances in your blood to calculate a Down Syndrome risk. The test is not invasive and does not harm you or your baby but it cannot be performed if you are an insulin dependent diabetic.
If you have already had either the nuchal scan or integrated test and have received a high risk result we recommend that you consider a diagnostic test like a CVS or amniocentesis rather than having another screening test.
How does the quadruple test work?
- A scan is performed to accurately date your pregnancy - for this test we cannot use any dating information from any previous scans that you may have had with this pregnancy.
- We ask you detailed questions about yourself and your pregnancy to assist with the screening test.
- A blood sample is taken and four substances are analysed - AFP, beta hCG, inhibin-A and oestriol.
We will call you with your results in four working days and will also email you a copy of the report.
What is in the report?
A screen positive indication will be given where the result of your quadruple Down Syndrome test has passed a certain threshold. The UK National Screening Committee has defined a 1:200 risk at birth as the screen-positive level for the quadruple test. If your result is 1:200 or higher you will be offered a diagnostic test, in this case an amniocentesis which will give you a definite answer.
How accurate is the quadruple Down Syndrome test?
Data from the Wolfson Institute has shown that in screening for Down Syndrome the quadruple test achieves a detection rate of 78%. The detection rate is the number of babies with Down Syndrome predicted by a positive test. This means that 22% of women with pregnancies affected with Down Syndrome will receive a falsely reassuring screen negative result which is incorrect.
The test achieves the detection rate with a screen positive rate of 3% - this is the number of babies who did not have Down Syndrome but were considered high risk by the test. Therefore 97% of women whose pregnancies are not affected with Down Syndrome will receive a screen negative result.
What happens if I have a multiple pregnancy?
Screening in twin pregnancies poses a difficulty because of the possibility that one fetus may be affected and the other may not. For this reason the quadruple test is only able to provide an overall risk for the pregnancy and not for each individual baby.
Where can I read more?
Download a copy of the Down Syndrome age risk chart.