All sonographers are registered and accredited with the Fetal Medicine Foundation in London . We are also an affiliated centre of Leeds Screening Centre.

Some facts.

• The vast majority of babies are born normal.
• All women, whatever their age, have a small risk of delivering a baby with physical and/or mental handicap.
• In some cases the handicap is due to a chromosomal abnormality such as Down's syndrome (trisomy 21).
• The NT scan gives an estimate of the risk for Down's syndrome.
• The only way to know for sure whether or not the fetus has a chromosomal abnormality is by having an invasive test such as chorionic villus sampling (CVS) or amniocentesis (amnio). However, invasive tests carry a 1-2% risk of miscarriage.

Risk for Down's syndrome in relation to Maternal Age
The table below shows how the chance of having a baby with Down's syndrome increases with age.

The traditional test, currently available on the NHS at 16 weeks, measures levels of hormones in the maternal blood and estimates a risk for Down's syndrome. This test identifies approximately 60% of affected babies with Down's syndrome.

Nuchal Translucency Scan
This ultrasound scan is carried out between 11 weeks and 13 weeks 6 days gestation, and measures the thickness of fluid at the back of the baby's neck. (Nuchal translucency).

We use a computer program that combines the gestational age of the baby, the nuchal translucency thickness and your age to calculate an estimate of your risk.

This test identifies approximately 80% of affected babies with Down's syndrome. At present this test is not available routinely on the NHS.

Nuchal Translucency scan + Blood tests
The most accurate way of estimating the risk of the baby having Down's syndrome combines the Nuchal Translucency scan with a blood test, which measures the level of hormones in the mothers blood - hCG and PAPP-A

This test identifies approximately 85-90% of affected babies with Down's syndrome.

Whichever test you decide to have, the scan has the benefit of checking:

• the gestational age of the baby
• whether there is more than 1 baby
• that the baby is developing normally

Booking the NT scan / combined test
You can phone us directly on 01772 866200 and book an appointment for your NT scan.

If you are having the combined test, the blood test can be done after 10 weeks gestation. It is recommended this is done at least a week before your scan in order for all the results will be available on the day of your scan.

However, you can choose to have the scan first and the blood test following this.

We will send you a blood sample pack and then you need to make an appointment with a health care professional for your blood test. The blood test is sent to Leeds Screening Service in a pre-packaged envelope.

We will liaise with Leeds Screening Centre and inform you directly of the test results. If the blood test is done following the scan, it will take between 3 - 5 days for the results to be available.

Payment
Payment for the NT scan is £100.00 and is payable on the day of the scan.

Assessment of risk - Your decision
The test gives you an estimate of the risk for Down's syndrome. It cannot tell you whether your baby is definitely affected. As a guideline, if the risk of Down's syndrome is higher than 1:250 then an invasive test such as an amniocentesis should be considered.