Contents
Blood tests are an important part of your care during pregnancy. They help to protect your own and your baby’s health. Some of the tests may be repeated routinely later in your pregnancy and this will be discussed with you. After a discussion and consent your midwife will take blood from your arm at one of your first visits and you should get the results at your next clinic visit.
What will I be tested for?
- Full blood count: This test will hep find out if you have anaemia – this means your blood is not good at carrying oxygen around the body. This can be treated with iron tablets and other treatments to support your health and the health of your baby.
- Blood group and Rhesus status: People belong to one of four blood groups, called A, B, O and AB. It’s important to know your blood group. The test will also show if you are Rhesus positive or Rhesus negative. If you are Rhesus positive, you do not need treatment. If you are Rhesus negative, there can be issues if your baby is Rhesus positive and if their blood enters your blood stream. This is unlikely to be an issue in a first pregnancy, but can be serious in future pregnancies. Your midwife will offer you an injection in your arm – the “anti-D” injection – that will help to protect your health and that of any future babies you may have.
- Infectious diseases: You will be offered blood tests for Hepatitis B, Syphilis and HIV. You will usually get the results at your next clinic visit, but you will be contacted sooner if an infection is found.
- Hepatitis B: This is caused by a virus which can be passed from mother to baby during birth. The virus can cause serious liver disease, but women carrying hepatitis B may have no signs of an infection. Without a test, they would not know they were infected. If a test shows you are infected with hepatitis B, you and your baby will be offered specialist treatment and immunisations following birth. If a baby is immunised following birth this will usually stop them getting hepatitis B and protect them from serious liver disease.
- Syphilis: Syphilis can damage your own and your baby’s health is not found and treated. It can be treated quickly and simply with antibiotics. People can have syphilis without realising it.
- HIV: HIV is the virus that causes AIDS. Over time, HIV damages the body’s defences against infection and diseases. People with HIV cannot be cured, but with treatment they can usually expect to live full and healthy lives. A woman who has HIV can pass the infection to her baby during pregnancy, birth and through breastfeeding. Women with HIV may not know they are infected until they have a test – it can take years for HIV to make someone ill. If your pregnancy screening test shows you may have HIV, you will be offered another test to check for sure. If this is confirmed, then you will be offered antiviral medications to keep you healthy and greatly reduce the chance of you passing HIV to your baby. Your Obstetrician and Midwife will give you advice about the safest way to deliver your baby and feed your baby. They will also tell you about medicines your baby can have after they are born to help protect against HIV.
You can find out more information on screening for infectious diseases by clicking here.
Sickle cell and thalassaemia
Sickle cell and thalassaemia are serious blood disorders that affect haemoglobin. Haemoglobin carries oxygen around the body. People who have these conditions need specialist care throughout their lives. You will be offered screening tests for sickle cell and thalassaemia at one of your first midwife visits.
People with sickle cell:
- Can have attacks of very severe pain
- Are more prone to serious life-threatening infections
- Are usually anaemic
- May need medicines and injections throughout their lives to stop them getting infections
People with thalassaemia:
- May be very anaemic
- May need regular blood transfusions
- May need medicines and injections throughout their lives to stop them getting infections
What causes these conditions?
Sickle cell and thalassaemia are passed from parents to children through altered genes. We inherit one gene from each parent. People only have these disorders if they inherit two altered genes – one from their mother and from their father. People who inherit just one altered gene are known as carriers.
What are carriers?
Carriers do not have sickle cell or thalassaemia. But if a carrier has a baby with someone who is also a carrier, or who has sickle cell or thalassaemia, there is a higher chance that a baby could have one of the disorders, or be a carrier. Anyone can be a carrier. However you are more likely to carry the gene if your parents or grandparents came from places where malaria was common, such as:
- An African country
- South Asia
- The Caribbean
- The Middle East
- South America
- Southern Europe
- East and South-East Asia
The Family Origin Questionnaire (FOQ)
To help find out if you or your baby’s father have a chance of carrying a gene for these conditions, your midwife will ask you questions from the FOQ form and take a blood test from you. The aim is to find out if you have a higher chance of carrying the altered gene. Your baby’s father may be invited for a blood test too, as testing both parents gives more accurate results.
What will the results tell me?
The most likely result is that you and your baby’s father are not carriers for sickle cell and thalassaemia. If one of you is, the pregnancy screening midwife will contact you and discuss what this could mean for you, your baby and your family. Results from your own and your baby’s father’s tests will then be used to see if your baby has a higher chance of developing one of the conditions.
Can my unborn baby be tested?
This test is not 100% accurate as this is still a screening test. Diagnostic testing is the only way to know for sure if your baby has or carries one of the conditions. All newborn babies are offered a blood spot test at around 5 days old. This test screens for nine conditions, one of these being sickle cell.