Blood tests offered in pregnancy

Blood tests are offered to all pregnant women. This is part of their antenatal care under the Maternity and Infant Care Scheme.

These blood tests are important for your health and your baby's health. They test for a wide range of conditions.

How much blood is taken

You will give only a small amount of blood during the test. This will be taken once, using one needle. This one sample of blood will be tested for a variety of viruses. You should feel no significant after-effects.

You will be offered these blood tests. Talk to your GP or midwife so you can decide if you want them or not.

Fear of needles

Tell the person who is taking the bloods if you are afraid of needles. Healthcare professionals deal with this issue often. They can help to make the experience easier for you.

Full blood count test for anaemia

This test checks for anaemia. Anaemia means that you have fewer red blood cells than normal or that your haemoglobin is low.

Haemoglobin is a protein in your blood that carries oxygen. Lack of iron is the most common cause of anaemia in pregnancy.

Anaemia can cause you to become very tired. Other symptoms include breathlessness and feeling faint. You may look pale. Less common symptoms of anaemia include heart palpitations and ringing in your ears.

If your iron levels are low, your GP, obstetrician or midwife may tell you to take iron supplements. Eating foods rich in iron may help.

You should also take foods and drinks with high levels of vitamin C. Vitamin C helps your body absorb iron. Avoid drinking tea at mealtimes as this can prevent your body from absorbing the iron in your food.

Blood group and antibodies

You will have your blood group and antibodies tested. The most important antibody tested is the Rhesus (Rh) Factor.

Rhesus (Rh) Factor

Rhesus factor is an inherited protein found on the surface of red blood cells. If your blood has the protein, you are Rhesus positive. If your blood lacks the protein, you are Rhesus negative.

If you are Rhesus negative and your baby is also Rhesus negative, there is no need to worry.

If your baby's father is Rhesus positive, there is a chance that your baby could be Rhesus positive. This could lead to your body producing antibodies against Rhesus. This might affect future pregnancies. It can also cause anaemia and jaundice in your child.

Anti D injections

Anti D injections prevent Rhesus negative women from producing these antibodies.

Rhesus negative women are all offered anti D injections at 28 weeks. They can have the injection again after the birth of their baby if the baby is Rhesus positive. This injection is safe for mothers and babies.

Page last reviewed: 26 March 2018
Next review due: 26 March 2021