About Blood Tests

These are performed at regular intervals during a pregnancy to make sure that you are staying healthy.


Booking Bloods

Booking Bloods

  • Full blood count – To check for anaemia
  • Haemoglobin screening – (If you are Asian or Afro-carribean) to check for
  • Sickle cell or Thalassaemia
  • Serology screening – to exclude Hepatitis, HIV and Syphilis
  • Blood group – to check which blood group and rhesus factor you are and to make sure you do not have any ‘antibodies’. These would need monitoring throughout pregnancy and may be an issue should you need a blood transfusion

Glucose Tolerance Test (GTT)

This is a specific test to check for diabetes. Timing of the test depends on your risk factors. Some women will be tested routinely and in early pregnancy, others will not be tested unless they develop sugar in their urine.

Reasons to have a GTT include:

  • Having a BMI of over 30
  • Asian origin
  • Previous pregnancy with gestational diabetes
  • Sugar in the urine (One high reading or two low readings)
  • Previous baby weighing more than 4.5kgs
  • Family history of diabetes

28 Week Bloods

Full Blood Count

Blood Group – to make sure no antibodies have developed during the pregnancy

PET Bloods

These are taken if you have high blood pressure, protein in your urine or both. They are checking your iron level, and kidney and liver function. (visit our High Blood Pressure page for more information)

Normal changes in pregnancy

Hb – your haemoglobin (Hb) level is affected by your iron levels. In pregnancy it is normal to appear slightly anaemic. This is due to extra fluid present in the blood so the blood dilutes itself slightly. This corrects itself after pregnancy. Any Hb level below 10.5 should be treated with a low level of iron treatment and monitored.

Kidney function (U&E)

Your Urea and creatinine levels should be below the normal range for a non-pregnant person. This is again due to the extra fluid in the blood and due to dilution.

Liver function (LFT)

The only change here is that your ALP will be raised. ALP is a hormone released by the liver and your bones. It is also released by the placenta which is why it is normally raised in pregnancy and nothing to be concerned about.