Screening tests during pregnancy

During your pregnancy you will be offered a number of screening tests. Your midwife will advise you which tests are offered and why.

These tests can help you find out more about your own health and the health of your baby before birth. Some of these tests are best taken before 10 weeks of pregnancy. Therefore, as soon as you know you are pregnant please contact your GP, Midwife or complete our online referral form:

so that we can arrange your first ‘booking’ appointment with the community midwife before 9 weeks to discuss all the options with you.

Do I have to have screening tests?

It is always your choice whether to have a test or not. The information which these tests can provide may help your midwife to provide the best care possible during your pregnancy and the birth. The test results may also help you to make choices about your pregnancy.

Questions you might like to ask and consider before deciding whether to have a test

  • What is the test for?
  • What does the test involve?
  • Will the test harm me or my baby?
  • What will the results show?
  • How and when will I get the results?
  • Who do I contact if I don’t get the results?
  • What happens if the test shows that there might be a problem?
  • What happens if I choose not to have the test?

Tests we offer

Blood tests

We routinely offer all women blood tests in the early stages of pregnancy to check for any potential problems. We recommend these tests are taken before 9 weeks of pregnancy. For women booking later than this we recommend the tests are taken as soon as possible. In addition to checking your haemoglobin for low iron level (anaemia), your blood group and rhesus factor, we also recommend screening for the following:

  • Sickle cell and Thalassaemia
  • Infectious diseases

Please follow this link to access the information leaflet on line for ‘Screening tests for you and your baby’.  This leaflet provides further details regarding the screening tests offered in pregnancy:

Please read this information leaflet before your first booking appointment, so that you have the information and knowledge to make a decision regarding these tests. Please also keep the leaflet safe so that you can refer to it for the screening tests which will be offered to your baby following birth.

If you have any questions the midwife at the booking appointment can answer them or refer you to one of our specialist screening midwives for support and further information.

Screening for a fetal anomaly

All pregnant women booking before 20 weeks of pregnancy are offered screening tests to assess the chance of there being a problem (or abnormality) with their baby. If a problem is suspected we may offer you a diagnostic test.

There are important differences between screening tests and diagnostic tests (see below). It is always your choice whether or not to have these tests. There is more information in the leaflet ‘Screening tests for you and your baby’.

Screening tests

A screening test is a way to find out if there is a lower or higher chance of your baby having a health problem. If the result is a ‘higher chance’ of a problem then you will be offered a diagnostic test.

Screening tests are not perfect. Some women will be told that their baby has a higher chance of a problem when they do not have a problem. Similarly, for a few women, they will be told they have a lower chance of a problem when in fact the baby does have a problem.

Diagnostic tests

A diagnostic test can tell you for definite that your baby has a problem. These tests examine your baby’s chromosomes. However, these tests do not detect every possible genetic or chromosome problem, only ones that are known.

Before you make any decisions on which antenatal screening tests to accept or not, it is important that you and your partner think about the implications of the result. You may find yourselves going through unnecessary worry or, in the worst case; you may find yourselves making a decision about whether or not to continue your pregnancy.

Remember that most babies develop normally and are healthy at birth. Your midwife or doctor can give you more information about these tests and discuss what the results may mean for you.

Screening for chromosomal and structural problems in pregnancy

Ultrasound scans

A pregnancy scan or ultrasound scan uses high-frequency sound waves to create a moving image of your baby and you can see the image on a screen. In most cases we are able to print out a photo for you and we charge £5 for 3 pictures. Also only one person may come with you to these scans, so that we can concentrate on performing the scan and giving you the most accurate information about the scan as possible.

Most women are routinely offered two ultrasound scans during pregnancy:

  • Dating Scan
    This scan is usually offered at around 11 weeks +2 days to 14 weeks +1 day. This is a quick scan taking only approximately 20minutes. The purpose of this scan is to:

    • check the size of your baby and view the heart beat
    • accurately confirm the due date
    • check for multiple pregnancies
    • carry out the scan as part of the combined screening test if you accept the screening (please see ‘Screening tests for you and your baby’ leaflet)

We occasionally do detect major abnormalities at this scan too. If we do detect a problem we will refer you to a specialist screening midwife and/or a doctor. They will talk to you in more detail, offer you support and talk about what happens next.

  • Anomaly Scan
    This scan is usually offered at around 20 weeks of pregnancy (Between 20 weeks + 0 days and 20 weeks + 6 days is the ideal time). This is a longer scan and takes approximately 30 minutes. The purpose of this scan is to:

    • provide a detailed examination to check the baby is developing normally
    • check the baby’s growth
    • check the location of the placenta
    • check the amount of amniotic fluid around the baby

If the scan shows a possible problem, you will be referred to a specialist to confirm findings and where necessary discuss the options available to you.

It is also, important to remember that not all abnormalities will be detected or seen on the ultrasound scan.

If you are above average weight or the baby is lying in an awkward position, we may not be able to check all the views of your baby. We will only offer you one more scan appointment to try and complete all the views.

Screening tests for Down’s syndrome, Edward’s syndrome and Patau’s syndromes

  • Down’s syndrome is also known as Trisomy 21
  • Edward’s syndrome is also known as Trisomy 18
  • Patau’s syndrome is also known as Trisomy 13

Anyone can have a baby with one of these conditions and they are not normally inherited.

There are two screening tests that can detect one or more of these conditions, the combined test and the quadruple test. You will be offered one of these tests and the availability of these tests depends on how pregnant you are.

Combined screening test

We offer the combined screening test between 11 weeks and 2 days up until 14 weeks and 1 day of pregnancy. Outside of these times the combined test cannot be offered. This test has two parts to it. The first part is an additional measurement of your baby, taken at the dating scan. The sonographer will measure the nuchal translucency (NT) this is the fluid around your baby’s neck.

The second part of the test is a blood test which needs to be taken immediately following the scan. If you do not have your blood taken following the scan the screening test cannot be undertaken. Then you will be contacted by letter informing you to attend for bloods. If you do not attend for the blood test after the first part of the combined test and you are more than 14 weeks +2 days you will be offered a quadruple test (details below).

You have a choice regarding the combined test of whether to be screened for all three of the conditions, just Down’s syndrome alone, just Edwards and Patau’s syndrome together or not to have the screening at all. The midwife who performs your booking will take your consent for these tests at that time, therefore it is important that you do read the ‘Screening tests for you and your baby’ leaflet.

Quadruple (or Quad) test

This screening test is offered to you only if your pregnancy is too advanced for the combined test. It is offered between 14 weeks + 2 days and 20 weeks + 0 days. It will only screen for Down’s syndrome and is a blood test.

If you are more than 20 + 0 weeks pregnant then we are unable to offer you any of the above screening tests for Down’s syndrome.

What happens if a problem is identified

Most babies, even when the result shows that there is a higher chance of a chromosomal problem, after a screening test, will have normal chromosomes. Unfortunately in a few cases we will confirm a problem either on scan or by a diagnostic/invasive test. In these cases we will tell you what the problem is and how this could affect your baby.

We will arrange specialist follow up care and discuss the options available to you. One of these options may be that you are offered a referral to a different hospital for further investigations. The specialist midwives for screening are also available for further information and support at this time

You can also contact ‘ARC’ (Antenatal Results and Choices)

They are a national organisation who can provide support and information about all aspects of screening and diagnostic tests. They are able to support families after a diagnosis of abnormality and provide online or telephone support around making difficult decisions around continuing or ending the pregnancy.