Quadruple (quad) testing for Down’s syndrome

Read our guide below about quad testing for Down’s syndrome.

You can also download a PDF version of this patient information by following the link on the right.

Why do I need a test for Down’s syndrome?

If it wasn’t possible to get a nuchal translucency measurement, or you’re more than 14 weeks into your pregnancy, we’ll offer you a test called the quadruple blood screening test. This happens between 14 and 20 weeks of pregnancy.

This only screens for Down’s syndrome and isn’t as accurate as the combined test.

Can this screening test harm me or my baby?

No it can’t harm you or the baby, but it’s important to consider carefully whether to have this test.

It can’t tell you for certain whether the baby does or doesn’t have Down’s syndrome, but it can give information that may lead to further important decisions. For example, we may offer you diagnostic tests that can tell you for certain whether the baby has these conditions. But these tests have a risk of miscarriage.

Do I need to have screening for Down’s syndrome?

You don’t need to have this screening test – it’s your choice. Some people want to find out the chance of their baby having these conditions while others don’t.
If you choose not to have the screening test for Down’s syndrome, you can still choose to have other tests, such as the 20-week scan.

If you choose not to have the screening test for these conditions, it's important to understand that if you have a scan at any point during your pregnancy, it could pick up physical conditions.

The person scanning you will always tell you if any conditions are found.

Getting your results

The screening test will not tell you if your baby does or doesnt have Down’s syndrome. It will tell you if you have a higher or lower chance of having a baby with this condition.

If your screening test returns a lower-chance result, we’ll tell you within 2 weeks by letter sent to your home address. If it shows a higher chance, one of the screening
midwives will contact you within 3 working days of the result to discuss the test results and the options you have.

Possible results

Lower-chance result

If the screening test shows that the chance of having a baby with Down’s syndrome is lower than 1 in 150, this is a lower-chance result. More than 95 out of 100 screening test results will be lower chance.

A lower-chance result doesn’t mean there’s no chance at all of the baby having Down’s syndrome, Edwards’ syndrome or Patau’s syndrome.

Higher-chance result

If the screening test shows that the chance of the baby having Down’s syndrome is higher than 1 in 150 (anywhere between 1 in 2 and 1 in 150), this is called a higher-chance result.

Fewer than 1 in 20 results will be higher chance. This means that out of 100 pregnancies screened for Down’s syndrome, fewer than 5 will have a higher-chance result.

A higher-chance result doesn’t mean the baby definitely has Down’s syndrome.

Will I need further tests?

If you have a lower-chance result, we won’t offer you a further test.

If you have a higher-chance result, you can decide to:

• not have any further testing
• have a second screening test called non-invasive prenatal testing (NIPT). This is a blood test,
  which can give you a more accurate screening result and help you to decide whether to have a diagnostic test or not
• have a diagnostic test, such as amniocentesis or chorionic villus sampling (CVS) straight away. This will tell you for certain whether or not your baby has Down’s syndrome, Edwards’ syndrome or Patau’s syndrome, but in rare cases can cause a miscarriage.

You can decide to have NIPT for:

• all 3 conditions
• Down’s syndrome only
• Edwards’ syndrome and Patau’s syndrome only

You can also decide to have a diagnostic test after NIPT.

NIPT is completely safe and will not harm your baby.

Whatever results you get from any of the screening or diagnostic tests, you will get care and support to help you to decide what to do next. Find out more.

Helpline support

Antenatal Results and Choices (ARC) is a charity which runs a helpline from Monday to Friday, 10am to 5.30pm on 020 7713 7486.

More help or advice

Contact our patient advice and liaison service (PALS) on 01296 316042 or bht.pals@nhs.net

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