3166YLH Screening for Down’s, Edward's and Patau's

Hello. All pregnant women are offered screening tests to assess the risk of their baby being born with Down’s, Edward’s or Patau’s syndromes. This video will tell you all about the syndromes and the tests, and what they mean for you and your baby. Down’s, Edward's and Patau's syndromes are genetic diseases. Every cell in the human body contains genes. Genes are responsible for how we grow and develop. They are grouped together in tiny structures called chromosomes. Usually, each cell contains 23 pairs of chromosomes. If there is an extra chromosome present, the additional genetic material can change how we develop. Down’s syndrome, also known as Trisomy 21 occurs when there is an extra copy of chromosome 21 in each cell. It affects 1 in every 1000 births. Down’s syndrome can cause physical and mental problems that range from being mild to severe. People with Down’s syndrome have characteristic facial features, but do still look like their parents. All children with Down's syndrome have some degree of learning disability and delayed development, but this varies widely between individual children. Around 1 in every 10 children also experience additional difficulties such as autism spectrum disorder (ASD)  or attention deficit hyperactivity disorder (ADHD). Because of these problems, children with Down's syndrome often require extra support as they grow up and additional help at school. Some children with Down's syndrome will have very few health problems. Others will experience several of the more common health conditions and will need extra medical care and attention. These include congenital heart problems, problems with their bowels and digestive system and problems with hearing and eyesight. Some problems can be serious but many can be treated and most people with Down’s syndrome are expected to live to around 60 years of age. These syndromes are caused by an extra copy of a chromosome in each cell – chromosome 18 in Edward’s syndrome and chromosome 13 in Patau’s syndrome. Both these syndromes cause serious physical and developmental abnormalities. Most babies will be stillborn or die shortly after birth. It is rare for babies with these syndromes to survive to adulthood. Edward’s syndrome affects about 3 in every 10,000 births and Patau’s syndrome affects about 2 in every 10,000 births. Screening tests are used to determine if your baby is at high or low risk of having a specific health problem. But they cannot tell you with 100% certainty. If the risk is high, you will be offered an appointment to discuss what this means, and whether you would like to have diagnostic tests to give you a more definite answer. The screening test for Down’s, Edward’s and Patau’s syndromes is called the combined test and is offered between 11 and 14 weeks of your pregnancy. It involves a blood test and an ultrasound scan which is done as part of your first pregnancy scan. These screening tests are safe for you and your baby. During your scan, the sonographer will measure the fluid at the back of the baby’s neck. The results of the blood test and the ultrasound scan, along with your age, are used to determine the risk of your baby having Down’s, Edward’s or Patau’s syndromes. If you are too far on in your pregnancy to have the combined screening test, an alternative blood test for Down’s syndrome called the Quadruple test, can be offered up until 20 weeks of pregnancy. Unfortunately this test cannot screen for Edward’s and Patau’s syndrome. However the physical abnormalities associated with these conditions are checked for as part of the 20 week scan. If your baby is found to be at high risk, you will be offered a diagnostic test to tell you whether your baby has one of these conditions. There are 2 tests available. ‘Chorionic villus’ sampling or CVS, is performed between 11-14 weeks of pregnancy, it involves taking a small sample of your placenta. The other test, called ‘amniocentesis’ or amnio is performed at around 16 weeks of pregnancy, and involves taking a small sample of amniotic fluid from around the baby. For both tests, a fine needle is passed through your tummy in to your womb. This does pose a very small risk of miscarriage. Miscarriage occurs in about one in every 100 tests. If the results show that your baby has one of these conditions, you will be given lots of support to help you decide whether you want to continue with your pregnancy, or to have an abortion. If you want any further information about the screening programme or these conditions, have a look at these websites. If you can’t find the answer, please get in touch with your community midwife or the specialist screening midwife at the hospital.