Introduction to screening
You will be offered screening tests during pregnancy to try to identify if you or your baby have a higher chance of any health problems, such as infectious diseases, Down’s, Edwards and Patau’s syndrome or physical abnormalities.
These tests can help you make choices about care or treatment during your pregnancy or after your baby is born.
To help you make informed decisions about screening, we recommend that you look at the following link: Pregnancy newborn screening
What are screening tests?
Screening tests are used to find people at higher chance of a health problem. This means they can get earlier, potentially more effective, treatment or make informed decisions about their health.
Screening tests are not perfect. Occasionally, some people will be told that they or their baby are at a high chance of having a health problem when they in fact do not have a problem. Also, a few people will be told that they or their baby have a low chance of having a health problem when in fact they do have a health problem.
What screening tests are used in pregnancy?
The screening tests offered during pregnancy are either ultrasound scans or blood tests, or a combination of both.
Ultrasound scans may detect physical abnormalities, such as spina bifida. Blood tests can help find the risk of inherited disorders such as sickle cell anaemia.
Blood tests combined with scans can help find the chance of chromosomal abnormalities such as Down’s syndrome.
Ultrasound scans use sound waves to build a picture of your baby in the womb. You will be offered a scan that produces a two-dimensional (2D) black and white image.
The scans are painless and have no known side effects to women or babies and can be carried out at any point in your pregnancy.
For most people, having a pregnancy scan is a happy event. But please be aware that ultrasound scans can detect serious health problems so try to be prepared for that.
This is usually your first scan. The sonographer will use this scan to take measurements of your baby and estimate your baby’s due date (estimated date of delivery).
The dating scan can include a nuchal translucency (NT) scan, which is part of the combined screening for Down’s syndrome, if you choose to have this screening.
Mid pregnancy ultrasound scan
A mid-pregnancy scan forms part of the antenatal screening programme that we offer.
It usually takes place at around 20 weeks and the main purpose of this scan is to look for abnormalities as it checks for 11 physical conditions in your baby. You may have heard it being referred to as an anomaly scan.
During the scan, we take a careful look at your baby from head to toe. Usually, we learn that the baby appears to be healthy and is developing well.
However, sometimes we may find a problem. Some problems are quite common, and others are rare. A few of these problems are serious, but most are minor, and any problems identified will be explained in detail to you.
Scans have their limitations. Sometimes we have to say there might be a problem but cannot say for certain. In a small number of cases, babies are born with abnormalities, even though no problem was identified by the scan.
What are the risks of screening tests?
Screening tests will not harm you or your baby, as far as we know the scans that we offer are safe for mother and baby. But there are some risks to consider. Some screening tests during pregnancy can lead to serious decisions for you.
For example, screening tests for Down’s syndrome comes with no risk, however if you are diagnosed with a high chance result, this can lead to difficult decisions about whether to have a diagnostic test that carries possible risk of miscarriage.
If the results of the diagnostic are positive, they can lead to a decision about whether you want to continue or end your pregnancy. Having further tests or termination will always be your decision, and health professionals will support you whatever you decide. You may want to think carefully about whether you want to have these screening tests or not.
When will I be offered screening?
Different screening tests will be offered at different times during pregnancy.
The screening test for sickle cell and thalassaemia should be offered before 10 weeks.
You will be offered screening for Down’s syndrome around the time of your dating scan, which happens when you are around 11 to 14 weeks pregnant.
You will be offered screening for abnormalities at a mid-pregnancy scan when you are around 18 to 21 weeks pregnant.
Will screening tests give me a definite answer?
No, a screening test does not usually say for certain if you or your baby have a health problem. It tells you if you or your baby have a high or low chance of having the problem.
Women of babies found to be at a high chance will be offered a diagnostic test, wherever possible. A diagnostic test does give a definite ‘yes’ or ‘no’ but comes with risk, such as miscarriage.
Do I have to have the screening tests?
No, you do not have to have the screening if you do not want to. It is a personal choice that only you can make, and it has to be the right decision for you and your family.
Some of the screening tests you will be offered are recommended by the NHS, such as:
- Blood tests for infectious diseases
- Eye screening if you have pre-existing diabetes (not gestational diabetes)
- Newborn checks
This is because the results from these tests can help to make sure that you or your baby get urgent treatment for serious problems.
Before having any screening performed, please remember that it is a clinical examination, and you will be asked to give consent before it is carried out. Make sure you understand what is going to happen – feel free to ask any questions.
What screening tests will my baby and I be offered?
You can find out more about the different screening tests by clicking the links below:
- Screening for infectious disease (hepatitis B, HIV and syphilis)
- Screening for inherited conditions (sickle cell, thalassaemia and other haemoglobin disorders)
- Screening for Down’s, Edwards’ and Patau’s syndrome
- Screening for abnormalities (18 to 21 weeks ultrasound scan)
Some screening tests will also be offered to your newborn baby. You can find out more about these tests by clicking the links below:
The results of any screening tests will be dealt with in strict confidence. No information about you, or your results, will be given to anyone outside of the care team without your consent or knowledge.
Some anonymous information is gathered for essential public health purposes. However, your privacy is protected and those receiving this information will not be able to identify you.
If you need to contact the specialist screening team they are available Monday to Friday between 9am and 5pm on 07971 228836.