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Nucal scan / Down’s syndrome

What is Down’s Syndrome?

Any woman, whatever her age, can have a Down’s syndrome child but the older a mother is the greater are her chances of having a baby with this condition. Down’s syndrome is a genetic disorder caused when the 23 pairs of chromosomes in each of the baby’s cells do not divide correctly which results in the baby’s cells having an extra copy of chromosome number 21.

What is Nuchal Translucency Scan (NT Scan)- combined test?

This test combines the results of:

  • 1. Nuchal scan (Ultrasound scan)
  • 2. Maternal blood test

It is a non invasive test which can be done to calculate the risk of your baby being born with a chromosomal abnormality such as Down’s syndrome. The scan can only be done between 11 weeks and 2 days and 13 weeks and 6 days of pregnancy.The test detects 90% of babies with chromosomal abnormalities and is not harmful to you or the baby.

Nucal Scan

1. Nuchal Translucency Scan (NT Scan):

A ‘nuchal translucency scan’ (NT) is a special ultrasound scan. During the scan the Sonographer will measure the crown-rump length of the baby allowing them to determine the correct age of the baby and measure the  fluid present behind the baby’s neck  called the Nuchal translucency.  All babies have this fluid behind the neck, however increased levels of this fluid can indicate a chromosomal abnormalities such as Down’s, Patau’s and Edward’s syndrome and major cardiac defects.   During this scan the Sonographer will also look at the baby’s features, such as the Nasal bone to see if there are any noticeable abnormalities.

2. Blood Test

The blood test measures the amount of two hormones in the mother’s blood (BHCG and PAPP-A). If the levels of these hormones are abnormal, it can indicate that the baby has a chromosomal abnormality such as Down’s syndrome.

Combined test result

The risk figure is calculated by a computer programme. Using the results of the Nuchal translucency scan, the blood test, size of the baby and maternal age, it allows you to see if you have a high risk or low risk of having a baby with a chromosomal abnormality.  The combined test cannot diagnose for certain whether the baby carries a chromosomal abnormality but can help you decide whether to have an invasive definitive test such as amniocentesis or chorionic villus sampling.

As the test is based on an individual baby it can be used to test for the risk of each baby in a multiple pregnancy.

For more information or to book an appointment please contact Diagnostic Healthcare’s team:
Tel:+44 (0) 161 929 5679
Email: info@dhc.uk.com