Blood tests

​Blood is much more than a red fluid that carries oxygen around the body. It is packed with living cells and looking at these cells can give clues about a baby’s overall health.

Blood also acts as the body’s transport system, moving nutrients, waste products and chemical messages around. Analysing a sample of blood can give masses of information about what is going on inside a baby. It is an essential way of monitoring his or her health.

Most samples are taken by pricking the skin to get blood from the back of the hand or the heel. These pricks leave tiny scars that are not permanent and do not affect the growth of the hand or foot.

Sugar levels

Blood needs to contain enough sugar to distribute energy to all of the body’s organs. Doctors want to know that the baby is managing to control the amount of sugar in his or her blood. They may give the baby supplements through one of the intravenous tubes. Babies born to diabetic mothers, or babies that had a very low birthweight may have problems maintaining blood sugar levels and need extra monitoring.


As well as carrying oxygen from the lungs to a number of organs, blood transports carbon dioxide from the organs to the lungs. Measuring the amount of these gases along with levels of acid can give clues about how well the baby is breathing and whether organs like the kidneys are meeting the baby’s needs.


Platelets are tiny fragments in the blood that play a part in preventing excessive bleeding. They are often found in reduced numbers in premature babies. If levels are very low, doctors may transfuse some platelets.


This is the protein that blood uses to transport oxygen. If babies have too few red blood cells and become ‘anaemic’, the amount of oxygen carried to the body’s organs may be below what the baby actually needs. If doctors find that a baby has anaemia, they may give a blood transfusion.

White blood cells

These cells play a big role in fighting infections. If levels in your baby’s blood are very low, doctors can give drugs to help your baby produce more and therefore be in a better position to fight off infections.

Newborn blood spot screening test

In the first week after birth, you will be offered a blood spot screening test for your baby. This test can identify babies who may have a rare or serious condition. Most babies screened will not have any of the conditions but, for the small number who do, the benefits of screening are enormous. Early treatment can improve their health and prevent severe disability or even death.

Further information is available from the UK newborn screening programme website.

Give blood

Many babies born prematurely or sick require blood or platelet transfusions. Blood and platelet donors have an essential role in giving these babies the best chance in life. Giving blood and platelets can help provide valuable support to vulnerable babies.