Prenatal testing and diagnosis

Prenatal testing

If you are about to have, or are currently undertaking, prenatal tests, it is important you understand about the tests you are taking, what they can tell you and what choices you may have to make. We know that this may be a difficult time for you. 

In many countries screening for Down syndrome is offered to pregnant women of all ages. The tests you will be offered depend on how many weeks pregnant you are. A screening test can only provide you with information about the likelihood of having a baby with Down syndrome.

Ultrasound scans can show signs that a baby has an increased chance of having Down syndrome. Certain blood tests can also detect if a baby is more likely to have Down syndrome. These include maternal serum screening tests and cell-free DNA testing (also called cfDNA or non-invasive prenatal screening (NIPT)). Compared to other screening tests, cfDNA testing can detect more of the pregnancies that have higher chances for Down syndrome. However, neither ultrasound nor blood tests can confirm a diagnosis.

To confirm a diagnosis, chorionic villus sampling (CVS) or amniocentesis (tests that take samples of foetal tissue or fluid from the baby) needs to be carried out.

It is your choice whether or not to take the tests. If you decide to take the tests, think about why you are taking the test, what the test can tell you and what choices you may have to make as a result of taking the test. It is important to source accurate, balanced and up-to-date information about Down syndrome. Information written by people with Down syndrome and their families can be particularly helpful. In many countries health professionals have received training to help women to make informed decisions that feel right for them. 

Explaining the diagnosis

In some countries health professionals have received training on how to deliver and explain the diagnosis. Receiving news about a diagnosis can be overwhelming and families often cope with a range of emotions during that time. Some parents and families also appreciate learning that Down syndrome is a natural condition that usually happens by chance and is not caused by anything they did or did not do during pregnancy. In addition to the health and social services available in some countries, local, national and international Down syndrome organisations can provide information, advice and support if required.