At your first antenatal appointment, known as the booking appointment, your midwife will explain about the different tests and checks on offer, including the reasons they give them. This will include ultrasound scans and other screening and diagnostic tests to check your baby’s development.
The same tests are offered to all pregnant women and it's your decision whether you have them.
Everything the midwife offers is there to help you and your baby but you have the right to refuse any tests that you are offered. If anything worries you about any of the tests, talk to your midwife.
Routine tests in pregnancy
These tests are done at your antenatal appointments to check your health and help spot certain issues that might crop up in pregnancy.
Blood pressure checks
Blood pressure is measured using a cuff that is wrapped around your upper arm. It's a good idea to wear a short-sleeved top for this. The reading from your first blood pressure check will give the antenatal team a starting point. From that reading they can see whether later readings are too high or too low for you. Blood pressure checks should ideally be done on the same arm every time.
Blood pressure is checked because raised blood pressure can be a warning sign of pre-eclampsia, a pregnancy condition that can be serious.
You will be asked to give a sample of your urine at your booking appointment to check for proteins and screen for any infections. Your urine is checked during antenatal checks for certain conditions that can be caused by pregnancy, such as pre-eclampsia and gestational diabetes. If you show any symptoms of having a urinary tract infection (UTI) at any time during your pregnancy, you will also be asked to give a urine sample.
The midwife, nurse or receptionist will give you a little pot to take into the toilet for this. It’s important to give a sample that is ‘midstream’ – this means it is taken halfway through weeing.
During pregnancy, your blood is tested for different things. Your midwife or doctor should explain this and tell you why the blood tests are being offered to you. They should also explain that it’s your choice whether you have the tests or not.
If you agree, the midwife will take a blood sample. If you are worried about the test, or afraid of needles, talk to your midwife about your concerns. These blood tests are usually taken only twice in pregnancy – you might have more if you need to be watched more closely for a specific reason. Your midwife or other medical professional will always talk to you first if you need more tests and will only take the blood test with your permission.
The first blood test will be offered in early pregnancy. This will look at:
- your blood group and rhesus status
- whether you have infections such as hepatitis B, HIV or syphilis
- anaemia (not enough iron in the blood)
- whether you are immune to German measles (rubella), a disease that can affect unborn babies
- whether you have blood conditions such as sickle cell anaemia or thalassaemia.
Later on in your pregnancy, around 28 weeks, you may be offered another blood test to check your iron levels again. In some cases, this test will also check whether you have developed pregnancy diabetes.
Measuring your baby’s growth
From 24 weeks your midwife will start to measure your growing bump to check that your baby is growing well. This is a simple test using a tape measure. She will measure your bump, in centimetres, from your bikini line to the top of the uterus. This will be plotted on a graph in your notes. The measurement should be the same as the number of weeks you are, give or take 1–2 cm.
Abdominal palpation (feeling your womb)
The midwife will feel your womb to check which position your baby is in. This will usually be performed at 36 weeks or earlier. This tells the midwife if the baby is in the right position for birth. They will usually listen to your baby’s heartbeat as well.
Other tests available (Group B Strep)
Group B Strep is a type of bacteria called streptococcal bacteria, which lives in the body. It is common (around 20% of women in the UK have it) and doesn’t usually cause any health problems.
The GBS bacteria do not produce any symptoms in women during pregnancy and your baby will usually be born healthy. However, there's a small risk it could spread to your baby during labour and make them ill. There’s also an extremely small risk you could miscarry or lose your baby.
Group B Strep not routinely tested for but may be found during tests carried out for another reason, such as a urine test or vaginal swab.
If you're worried about group B strep, speak to your midwife or GP for advice. Routine testing isn't currently recommended and tests are rarely done on the NHS, but you can pay for one privately.
Find out more about Group B Strep in pregnancy.