Pregnancy Blood Test Timeline: Complete Guide
Blood tests are one of the least talked-about parts of antenatal care, yet you'll have several rounds of them across pregnancy. Knowing roughly when each one happens — and why — can make the appointments feel far less daunting, especially if you're not keen on needles.
Booking appointment (around 8-12 weeks)
This is the biggest single round of blood tests you'll have. Your midwife will usually take several vials at once to check:
- Blood group and rhesus (Rh) factor — important for planning care if you're Rh negative
- Full blood count — screens for anaemia, which is common and easily treated with iron
- Haemoglobinopathy screening — checks for sickle cell trait/disease and thalassaemia
- Infectious disease screening — HIV, syphilis, and hepatitis B, all treatable in pregnancy to protect your baby
- Rubella immunity — in some areas, to flag if you'd need to avoid contact with the virus
All of these are offered, not compulsory, and your midwife will talk through what each one involves before taking blood.
Combined screening bloods (11-14 weeks)
If you opt into combined screening for Down's, Edwards' and Patau's syndromes, a blood sample measuring hCG and PAPP-A levels is taken alongside your 12-week scan measurements. Together these feed into a single risk score — the blood test alone doesn't give you a result.
Later pregnancy blood tests
- Around 28 weeks — a repeat full blood count to check for anaemia as your blood volume expands, plus antibody screening
- Anti-D — if you're Rh negative, you'll be offered anti-D injections (usually preceded by a blood test) to prevent complications in this or future pregnancies
- Glucose tolerance test — offered between 24-28 weeks if you have risk factors for gestational diabetes
- Group and save — often done shortly before birth so blood is ready to cross-match if you need a transfusion
Your midwife may add extra tests depending on your individual history, ethnicity, or any symptoms that come up along the way — so your exact timeline can differ slightly from a textbook one.
Getting the most out of your appointments
It's worth asking your midwife which results you'll be told automatically and which you need to actively ask about — not every unit contacts you unless there's a problem, so a "no news" approach can leave some people wondering. If you're anxious about needles, mention it; many midwives can use a smaller needle, let you lie down, or talk you through the process to help. Staying hydrated beforehand can also make it easier for the phlebotomist to find a vein, and eating a small meal beforehand can help if you're prone to feeling faint around blood tests.
Frequently Asked Questions
What blood tests are done at the booking appointment?
Your booking bloods typically cover blood group and rhesus factor, a full blood count for anaemia, sickle cell and thalassaemia screening, and infectious disease screening for HIV, syphilis and hepatitis B. Rubella immunity may also be checked in some areas. These are all offered rather than mandatory, and your midwife will explain the purpose of each before you consent.
When do I get blood tests in pregnancy?
The main rounds are at your booking appointment (roughly 8-12 weeks), alongside combined screening bloods (11-14 weeks) if you choose that test, and again around 28 weeks to recheck for anaemia. Additional tests, such as a glucose tolerance test or a pre-birth group and save, may be added depending on your risk factors and local guidelines.
Do I have to have all the recommended blood tests?
No — every blood test in pregnancy is offered, not mandatory, and you can decline any of them after discussing it with your midwife. Some parents choose to skip certain screening tests but keep others, such as anaemia checks. If you're unsure, ask your midwife to talk through what each test means for your care so you can make an informed decision.
This article is for informational purposes only and does not constitute medical advice.
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