Pregnant women are offered screening for Edwards’ syndrome between 10 and 14 weeks of pregnancy to assess the chances of their baby having the condition.
The screening test, known as the combined test, comprises a blood test plus a nuchal translucency ultrasound scan (nuchal translucency is a collection of fluid at the back of the baby's neck). This test also screens for Down’s syndrome and Patau’s syndrome.
Later in pregnancy, usually when you are 18 to 21 weeks pregnant, you will also be offered a scan that looks for physical abnormalities and 11 rare conditions, including Edwards’ syndrome.
If the screening tests show that you have a higher risk of having a baby with Edwards' syndrome, you will be offered diagnostic tests to find out for certain if your baby has the condition.
The diagnosis can be confirmed by carrying out chorionic villus sampling or amniocentesis. These are invasive tests performed during pregnancy to remove a sample of tissue or fluid so it can be tested for the presence of the extra copy of chromosome 18.
A newer test has also been developed that can be performed by taking a sample of blood from the mother and testing the baby’s DNA that is found within it. This is known as "non-invasive prenatal diagnosis" and is only available privately.