BLOOD TESTS 2020-05-18T05:59:49+00:00


Blood Tests


As part of your antenatal care you will be offered several blood tests. Some blood tests are offered to all women, while others are only offered if you may be at risk of a particular inherited condition or infection.

All tests are done to check for any problems that may occur during or after your pregnancy, or to make sure your baby is healthy. You do not have to undergo these tests if you do not want to.

It is important to talk to your midwife or doctor to ensure you are fully informed about your options and get written information about the tests.


There are a number of blood tests that can be performed, these include:

  • Blood group
  • Anaemia
  • Full blood profile
  • Infection tests
  • Antibody screening
  • Thyroid function


There are four blood types, and a blood test will be given to figure out which group you are in. It is important to know your blood type in case you need to be given blood during pregnancy or birth.

Your will also be able to find out your Rhesus factor, which is whether your blood is positive or negative. If your blood type is negative there isn’t usually any problem, unless your baby has a positive blood type. If this is the case your body may produce antibodies against your baby’s blood, which can impact on future pregnancies.


In addition to women with a negative blood type who have a baby with a negative blood type, any woman who has had a prior pregnancy or a blood transfusion may produce antibodies that can harm the baby. An antibody screen will be done during the first trimester and will be repeated during the third to determine if the mother has any potentially harmful antibodies in her bloodstream.

The baby’s father may be tested if any harmful antibodies are detected in the mother, to see if he has any antibodies that the mother’s body may target.


It is common for a woman to develop an iron deficiency during pregnancy. This is caused by your body’s need for extra iron to supply your baby with sufficient blood supply and necessary oxygen and nutrients. Increasing the amount of iron you consume in your diet can help prevent iron deficiency.

Some women will require iron supplements, particularly after the 20th week of pregnancy. Anaemia can make you tired and less able to cope with possible blood loss during labour and birth.

Your midwife or doctor will be able to tell you if you need iron tablets, and your iron levels will be checked throughout your pregnancy.


Your blood tests will also look for certain infections that can affect your pregnancy or your unborn baby. The infections can include:

  • Syphilis
  • Hepatitis B
  • Hepatitis C
  • Rubella
  • HIV

It is important to remember that you are still able to catch any of these infections during pregnancy.

If any of your tests come back with abnormalities your doctor will notify you as soon as the results are available.

If you have any further queries, our friendly team at My Obg will be happy to assist you. Call us on (03) 9731 1006 or email us at