Routine antenatal tests
blood; test; urine; iron; deficiency; haemoglobin; group; rubella; immunity; hepatitis; B; syphilis; HIV/AIDS; HIV; AIDS; C; Rhesus; Rh; positive; negative; pap; smear; HPV; cervical; cancer; gestational; diabetes; bladder; urinary; tract; infection; glucose; challenge; immunisation;
There are a number of blood tests and other types of routine tests that will be offered to you during your pregnancy. These tests are designed to pick up certain illnesses or other possible problems such as anaemia.
If any health problems are picked up by these tests, the problem can often be treated during pregnancy or immediately after birth, allowing you and your baby to stay as healthy as possible.
Another test that is routinely done is an ultrasound test at about 19 weeks. Have a look at the topic 'Ultrasound scan'.
Your doctor or midwife can provide you with more information about these tests.
There are some other tests that you may be offered, see 'Screening tests (checking your baby's health before birth)'.
Blood tests during pregnancy
When you have your first antenatal visit, it is usual for your doctor or midwife to offer a series of tests on your blood.
- Your doctor or midwife will take some blood and send it to be tested for haemoglobin, your blood group, rubella immunity, hepatitis B, syphilis, HIV and hepatitis C.
Doing all these tests at once means that you will have the results as early as possible during your pregnancy and you will not have to have your blood taken more times than absolutely necessary.
The results of these tests will usually be available at the time of your second antenatal visit. The following sections provide more information about the conditions that are tested for and why the results are important to pregnant women.
Checking your blood group
Your blood will be tested to check your blood group.
- It is important to know your blood group in case you ever need a blood transfusion.
- There are four main blood groups or types – A, B, AB and O.
Rh negative blood and Anti D injections
85% of the population have an additional blood group factor called Rhesus D (Rh D). They are Rh positive. The remaining 15% of the population lack the factor and are therefore Rh negative.
Pregnant women who are Rhesus (Rh) negative may need to have an Rh D immunoglobulin (commonly called Anti-D) injection to safeguard their babies.
If an Rh negative woman becomes pregnant to an Rh positive man, their baby may be Rh positive or Rh negative.
- If the baby is also Rh negative there will be no Rh problems.
- If the baby is Rh positive, there is a risk that some of its Rh positive blood cells may enter the mother’s bloodstream during the pregnancy or birth.
- If this is left untreated, the mother will develop antibodies to the baby's Rh positive blood.
- If a mother develops antibodies, these antibodies will cross the placenta and may destroy a baby's red blood cells, in this or in future pregnancies.
- If not treated these babies may be anaemic, or at risk of brain damage or even die before birth.
- An injection of Anti-D can be given to an Rh negative mother, which helps stop her immune system making antibodies to the baby's Rh positive cells.
If you are Rh negative and have not formed antibodies:
- You will be offered an Anti-D injection at 28 weeks and at 34 weeks of your pregnancy.
- You will also be offered an Anti-D injection if you have:
- any vaginal bleeding during your pregnancy
- a miscarriage
- an abortion
- a medical procedure such as chorionic villous sampling (CVS) or amniocentesis.
You will be given an Anti-D injection within 72 hours of your baby's birth if your baby is Rh positive.
- This information is taken from the Flinders Medical Centre pamphlet: Rhesus (Rh) Negative Blood and Pregnancy.
Your doctor or midwife will offer you a blood test to measure the haemoglobin in your blood.
- This test is usually done at your first antenatal visit.
- Your doctor or midwife may also repeat this test later in your pregnancy (around 28 to 30 weeks).
Haemoglobin is a substance that carries oxygen to every cell in your body.
- Our bodies use iron to produce haemoglobin.
- When you are pregnant, you need much more iron than usual to produce enough haemoglobin and to lay down iron stores for your baby.
If a blood test shows that your haemoglobin level is low, this is called anaemia.
- If you have anaemia, you may feel tired, get short of breath, find it hard to concentrate, feel irritable and be more prone to infections.
- Anaemia can also make it more difficult for your body to cope with losing blood, such as when you give birth to your baby.
Once anaemia has been picked up by a blood test it is usually easy to treat by eating more iron-rich foods. Your doctor may also prescribe iron tablets.
To learn more about your iron requirements in pregnancy and for a list of iron-rich foods see Eating well in pregnancy.
Rubella is usually a mild infection that is also known as German Measles.
- Although the infection causes only mild symptoms in children and adults, rubella can cause serious problems for your unborn baby, such as blindness and deafness if you catch it in the early months of your pregnancy.
The blood test is performed to check whether or not you are immune to rubella.
- Most Australian women are immune to rubella, because they were vaccinated against the disease when they were teenagers at school.
- When you are immune to rubella, it means you won't catch the virus even if you come into contact with it.
- Both boys and girls are now vaccinated against rubella when they are 12 months old and again at 4 years.
If you are not immune to rubella, it is very important that you avoid coming into contact with anyone who has rubella.
- Once you have had your baby, you can be vaccinated against rubella.
If you are not immune to rubella and do come into contact with someone who has the infection, or you develop any kind of rash during pregnancy:
- Tell your doctor or midwife as soon as possible, as they may be able to give you an injection that will give you short term protection.
- A blood test can be done to check if you have caught rubella.
- If you do catch rubella during the first 16 weeks of your pregnancy, you will be offered some special tests to see if your baby has also been infected with rubella.
- Syphilis is a sexually transmitted disease that is quite uncommon today - but it is still vital to detect and treat women who have this infection.
- Early treatment can prevent the unborn baby from being infected.
- For more information, have a look at the fact sheet 'Syphilis'.
Hepatitis B is a virus that is usually spread through blood to blood contact with an infected person, through sexual contact, or from a mother to child at birth. Hepatitis B virus affects the liver and can cause fever, nausea, tiredness, dark urine and yellow skin (jaundice).
- Most babies and young children who are infected become carriers of the infection and can continue to spread it to other people.
- These carriers are also at increased risk of developing liver disease and liver cancer later in life.
To protect against hepatitis B, all babies born in Australia are offered their first hepatitis B immunisation within seven days of birth. They then need 3 more doses at 2, 4 and 6 months of age.
If your blood test shows that you have hepatitis B (or you already know that you have it), your baby can be given a special injection of a substance called immunoglobulin within 12 hours of their birth as well as the hepatitis B vaccine to give increased protection.
- If you have hepatitis B, it is very important for your baby to receive both the immunoglobulin and the usual hepatitis B immunisation. This will give your baby a high level of protection.
- Your doctor or midwife can provide you with more information about these injections.
There is more information about the immunisation for hepatitis B that is given to babies in the topic 'Hepatitis B vaccine at birth'.
For more information you could look at
- Hepatitis C is a different type of hepatitis virus that can cause damage to the liver. Hepatitis C is spread through blood. This means that injecting drugs or having a tattoo (especially if it wasn't done by a professional tattoo artist) may spread the infection.
- Hepatitis C testing is currently offered routinely to pregnant women in South Australia. You may opt to have this test if you have had close contact with someone who has hepatitis C or if you have ever injected drugs.
- People with hepatitis C don't always feel unwell, so a blood test is the only way of checking if you have the virus. If you think you could be at risk of hepatitis C, please discuss having this blood test with your doctor.
- There is no immunisation which protects against hepatitis C.
- The risk of mother to baby spread during pregnancy and childbirth is very low unless the mother is also infected with HIV.
- Women who are positive for hepatitis C are encouraged to breastfeed, but may need to stop feeding temporarily if they develop cracked nipples until the nipples heal.
For more information you could look at the Department of Health fact sheet Hepatitis C.
HIV and AIDS
AIDS is caused by the human immunodeficiency virus (HIV). It can cause serious illness to affected people.
In Australia, most infections have resulted from:
- unprotected sex (anal and vaginal intercourse)
- sharing injecting equipment
- receiving blood or blood products before the introduction of screening in 1985
- mother-to-baby transmission during pregnancy, birth or breastfeeding.
Routine social or community contact with an HIV infected person carries no risk of infection.
HIV doesn't just affect homosexuals and drug users. It is possible to be HIV positive for a number of years and not know it.
- Although testing for HIV is not generally considered a routine antenatal test it is currently offered by most hospital antenatal clinics.
- You may choose whether you want to have this blood check along with your other blood tests or not. A blood test for HIV will be especially important if you have had unprotected sex and did not know your partner's HIV status or if you have ever injected non-prescription drugs.
- Your doctor or midwife should be able to inform you and explain to you what a positive or negative result will mean.
- If you are worried about having a test for HIV, or do not want it done, please discuss this with your doctor or midwife.
For more information
NSW Health 'I'm pregnant. Do I need an HIV test?'
SA Department of Health Fact sheet Human Immunodeficiency Virus
On your first antenatal visit, your doctor or midwife will ask you to collect a sample of your urine.
- Your urine will then be tested for a bladder or urinary tract infection.
- Sometimes you can have this type of infection without having any symptoms.
- If you have an infection, it can be treated with antibiotics.
- Untreated urinary tract infections can lead to serious kidney infections and pregnancy complications.
Glucose challenge test for gestational diabetes
Gestational diabetes is a type of diabetes that develops only in pregnancy.
- The condition occurs in two to three of every 100 pregnant women.
- Gestational diabetes usually lasts only while you are pregnant, but once you have had it, it is likely that it may also occur in future pregnancies, and it also means that you are at risk of developing diabetes later in life.
If gestational diabetes is not discovered and treated, it may cause problems for the mother and/or baby.
- The baby may become very big and have difficulties being born.
- The baby may become sick and have breathing problems after birth.
These problems can be greatly reduced, or even prevented, if the condition is diagnosed and the mother treated.
- Treatment is usually by a special diet and, sometimes, insulin injections.
- Women with gestational diabetes need to carefully watch their blood sugar levels.
To discover if you have diabetes, it is important that you have a screening test.
- This is normally done around 24–28 weeks.
- You will be given a special glucose drink before your test and have a blood sample taken exactly one hour later.
- If you have a raised blood glucose level, it doesn't necessarily mean that you have diabetes, but you will need to have further testing to find out whether you have it or not.
There is more information in the topic 'Gestational diabetes'.
Your doctor or midwife will usually do a blood test for anaemia at the same time. Some women who were not anaemic early in their pregnancy may develop anaemia by this stage.
Pap smear (smear test)
- A Pap smear is a simple test that takes only a few minutes. If you are due for a Pap smear your doctor or midwife will suggest you have one at your first antenatal visit.
- The test is used to collect cells from your cervix. When these cells are examined under a microscope, health professionals are able to see changes to your cells before they become cancerous.
- With regular Pap smears, these early changes can be found and treated before cancer has a chance to develop.
- Pap smears are an important screening test for all women up to 70 years old who have ever had sex.
Where is the cervix?
- The cervix is the lower part of your uterus. The uterus is also called the womb and the cervix is sometimes called the neck of the womb.
- During labour, your cervix will stretch to allow your baby to pass down into the birth canal (vagina).
How is a Pap smear done?
- To collect cells for the smear test, your doctor will insert an instrument called a speculum into your vagina so that he or she can easily see your cervix.
- Your doctor then collects cells from your cervix with a small brush and smears them on to a glass slide.
- The slide is sent to the laboratory for expert examination under a microscope.
- Having a smear test can sometimes feel a bit uncomfortable, but should not be painful.
- Many young women have been immunised against the most common viruses that are linked to cervical cancer (human papilloma viruses or HPV).
- Even if you have been immunised you still need to have pap smears because HPV vaccination will not prevent all cases of cervical cancer and some women will already have cell changes before they were immunised.
For more information about pap smears:
The information on this site should not be used as an alternative to professional care. If you have a particular problem, see your doctor or midwife.