thumb image

During your pregnancy, you’ll be offered a range of tests, including blood tests, as well as regular urine and blood pressure tests.

These are designed to:

  • help make your pregnancy safer
  • check and assess the development and wellbeing of you and your baby
  • screen for particular conditions

You don’t have to have any of the tests – it’s your choice. However, it’s important to understand the purpose of all tests so you can make an informed decision about whether to have them. You can discuss this with your community midwife.

For a useful timeline of tests and screening offered to you and your baby see the Public Health England document here.


You’ll be offered some screening tests during pregnancy to try to find any health problems that could affect you or your baby, such as infectious diseases, Down’s syndrome, or physical abnormalities.The tests can help you make choices about further tests and care or treatment during your pregnancy or after your baby’s born. All screening tests offered by the NHS are free. For more information about screening tests for you and your baby please take a look at the this booklet. You can find out more about screening tests for anomalies by visiting the NHS website here.


At your booking appointment your midwife will offer you carbon monoxide (CO) breath testing. Carbon monoxide is a colourless, odourless and tasteless poisonous gas. You can’t see it or smell it but it is in cigarette smoke. CO is also present in faulty gas boilers and car exhaust fumes.

It is dangerous because it deprives the baby of oxygen, slows its growth and development, and increases the risk of miscarriage, stillbirth and sudden infant death. The test is simple and easy and will show how much of this gas you and your baby have been exposed to.

For more about carbon monoxide breath testing find link here.


Sickle cell disease (SCD) and thalassaemia are inherited blood disorders. If you are a carrier of sickle cell or thalassaemia, you can pass these conditions on to your baby.

All pregnant women in England are offered a blood test to find out if they carry a gene for thalassaemia, and those at high risk of being a sickle cell carrier are also offered a test for sickle cell. If the mother is found to be a carrier, screening is also offered to the father.

Read more about sickle cell and thalassamia here.


It’s useful to know your blood group in case you need to be given blood – for example, if you have heavy bleeding (haemorrhage) during pregnancy or birth.

The test tells you whether you are blood group rhesus negative or rhesus positive. Women who are rhesus negative will be offered injections during pregnancy to reduce the risk of rhesus disease.

Rhesus disease can happen if a pregnant woman who is rhesus negative develops antibodies that attack the baby’s blood cells. This can lead to anaemia and jaundice in the baby.

Find out more about rhesus disease here.


Anaemia makes you tired and less able to cope with loss of blood when you give birth. You should be offered screening for anaemia at your booking appointment and at 28 weeks.

If tests show you’re anaemic, you’ll probably be offered iron and folic acid. Read more about anaemia here.


You’ll be offered a blood test for three infectious diseases:

  • HIV
  • Hepatitis B
  • Syphilis

These tests are recommended to protect your health through early treatment and care, and reduce any risk of passing on an infection to your baby, partner or other family members.

Read more about screening for HIV, syphilis and hepatitis B here.


Your community midwife may inform you that you could be at higher risk of developing diabetes in pregnancy (gestational diabetes)

In this case, you will be offered a test called the GTT (oral glucose tolerance test). This involves drinking a sugary drink and having blood tests.

The GTT is done when you’re approximately 28 weeks pregnant. If you’ve had gestational diabetes before, you’ll be offered:

  • early self-monitoring of blood glucose levels, or
  • a GTT earlier in pregnancy, soon after your booking visit, and another at 24 to 28 weeks if the first test is normal

Read more about gestational diabetes here.


Ultrasound scans use sound waves to build a picture of the baby in the womb. The scans are painless, have no known side effects on mothers or babies, and can be carried out at any stage of pregnancy. Most scans are carried out by specially trained staff called sonographers.

For many women, ultrasound scans are the highlight of pregnancy. It’s very exciting to “see” your baby in the womb, often moving their hands and legs.

Remember, an ultrasound scan is an important medical examination and it is treated in the same way as any other hospital investigation.

All pregnant women in Gloucestershire are offered at least 2 ultrasound scans during their pregnancy one at 8 to 14 weeks and the second between 18 and 21 weeks.

Talk to your midwife, GP or obstetrician about any concerns you have.

Read more about Ultrasound scans in pregnancy here