Your choice of accurate screenings...

Please read this short explanation by clicking on a question to take you to the answer, then select the service you require from the list on the left.

What is Down Syndrome?

What is a Screening Test?

How is the result of a Screening Test given?

Should I have a Diagnostic Test?

What Down Syndrome Screening services do you offer?

Why should I choose The London Ultrasound Centre for my Down Syndrome Screening?

Where do I find more information about the tests?

Download Down Sydrome Age Risk Chart

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What is Down Syndrome?
Down Syndrome is a genetic disorder that is caused by the presence of an extra copy of chromosome 21.

Anyone can give birth to a baby with Down Syndrome and the chances of having a Down’s baby rise with the age of the mother. Usually it is not inherited and a baby can be affected even if there is no previous history of Down Syndrome in your family.

All mothers to be in the UK should be offered Down Syndrome screening through the NHS.

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What is a Screening Test?
A screening test is one to determine the chances of the mother giving birth to a baby with Down Syndrome. It cannot tell if your baby definitely has the disorder. Only a diagnostic test can definitively provide a yes or no answer.

A screening test uses a set of known risk factors to input into a complex mathematical calculation which can determine your personal risk factor. The result will expressed as a ratio, much like your chances of winning the lottery are published (e.g. almost 1:14 million in the UK).

In addition to Down Syndrome screening the test results will also reveal information about the chance of other common chromosome anomalies; Edward's Syndrome (chromosome 18) and Patau Syndrome (chromosome 13). 

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How is the result of a Screening Test given?
All screening tests have a clinically agreed figure that is the border between high and low risk. If you are high risk your result will be described as ‘screen positive’ and you will be offered a diagnostic test to obtain a definitive answer. It’s important to remember that most screen positive results when subjected to a diagnostic test will prove to be false. These are known as false positive screenings.

If your Down Syndrome screening produces a low risk result (i.e. ‘screen negative’) you will not be offered a diagnostic test, but that does not mean that you cannot have one if you want to. It’s equally important to keep in mind that a very small number of low risk screenings will not detect a baby that has Down Syndrome.

Unless your screening test has been unsuccessful it is seldom useful to repeat a screening for Down Syndrome as you will always receive a different risk result which can prove confusing. If you are unhappy with your first screening you should consider a diagnostic test.

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Should I have a Diagnostic Test?
Ultimately the choice about whether to have a diagnostic test rests with you and your partner and not your doctor. If you are the sort of person who never like to takes risks you may decide to have a diagnostic test after your screening or even bypass the screening all together. Of course like all medical procedures a diagnostic test is not risk free, so you will have to weigh up your risk of having a Down Syndrome baby against the risk of miscarriage by having an invasive procedure.

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• The Combined Nuchal Scan (First trimester)
• The Quadruple Test (Second trimester)
• The Integrated Test (First & second trimester)

• CVS (12 – 14 weeks gestation)
• Amniocentesis (16 weeks gestation onwards)

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Why should I choose The London Ultrasound Centre for my Down Syndrome Screening?
If you choose to have your Down Syndrome screening at the London Ultrasound Centre you will receive an efficient service, performed by highly qualified experts, using the latest and most accurate techniques

In addition we are able to provide support, counselling and the offer of a diagnostic procedure should the result of your screening produce a high-risk answer.

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Where do I find more information about the tests?
You can download our Down Sydrome Age Risk Chart here and for more information on our screening and diagnostic tests please click on the links above or the menu on the left.