Tests, scans and checks - pregnancy and labour
Summary
Tests can confirm your pregnancy and also monitor your baby’s development in the womb.
If you think you could be pregnant, you can see your general practitioner (GP) or family planning clinic for a
pregnancy test.
Ultrasound is used during pregnancy to check your baby's development and to help see if anything is wrong.
Amniocentesis is a test that may be done during pregnancy to check for birth defects such as Down
syndrome, cystic fibrosis or spina bifida.
Chorionic villus sampling (CVS) is a test that may be done during pregnancy that checks the baby for some
genetic conditions such as Down syndrome or cystic fibrosis.
There is a very small risk of the amniocentesis and CVS tests causing a miscarriage.
Some women develop temporary diabetes during pregnancy. ‘Gestational diabetes’ is diagnosed using an
oral glucose tolerance test.
A range of tests is available if you are pregnant. These tests can confirm your pregnancy and also monitor your
baby’s development in the womb. No medical test is ever 100 per cent accurate, but most pregnancy tests are
very reliable.
Regular check-ups with your doctor or midwife are an important part of pregnancy care, including information and
advice about what tests you and your baby will need.
Prenatal tests
As well checking the general health of the mother and baby, the different kinds of tests available to pregnant
women include:
tests to confirm pregnancy
maternal health screening
routine screening tests (these tell you how likely it is that your baby has a certain health condition)
diagnostic tests – for pregnancies at increased risk (these tell you more accurately if your baby has a certain
health condition).
For more information see the Pregnancy – prenatal tests fact sheet.
Testing to confirm pregnancy
If you think you could be pregnant, you can see your GP (or family planning clinic) for a pregnancy test. The doctor
may perform a pregnancy test on your blood or urine. Alternatively, you could buy a home pregnancy test kit, which
are available from pharmacies. However, always see your doctor for confirmation of pregnancy if you use a home
kit.
The typical pregnancy test checks a woman's blood or urine for the presence of a substance called human
chorionic gonadotropin (hCG). This is a hormone made by the placenta. When the hCG hormone is present, it
usually indicates that the woman is pregnant. A home pregnancy test can give false positive or false negative
results.
For more information see the Pregnancy testing fact sheet.
Maternal health screening
During your pregnancy you will have blood tests to check:
your blood type – it is important to know if you are Rh-negative as problems can occur during pregnancy if
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an Rh-negative woman carries an Rh-positive baby
whether you are immune to rubella (German measles)
whether you have any infections (such as HIV, hepatitis B, rubella or syphilis, among others)
your iron levels
whether you have gestational diabetes.
You will also have:
a urine test early in pregnancy to check for urine infections (which, left untreated, can lead to early labour or
babies with low birth weight)
a vaginal swab test at 36 to 38 weeks to check for group B streptococci (which can pass to your baby during
birth and make them very sick).
If you are considered to be at higher risk, you may also have tests for:
hepatitis C
chlamydia
asymptomatic bacterial vaginosis
vitamin D deficiency.
Rh type
Problems can occur during pregnancy if an Rh-negative woman carries an Rh-positive baby. For this reason, a
blood test is carried out early in pregnancy to determine the mother’s blood type. If you are Rh-negative you will
be offered an Anti-D injection:
at your 26 to 28 week antenatal appointment
at your 34 to 36 week antenatal appointment
after giving birth (if your baby is Rh-positive).
Anti-D is a special injection that will prevent an Rh-negative mother’s immune system from rejecting her baby’s Rhpositive red blood cells.
For more information see the Blood groups fact sheet.
Rubella
A rubella infection is mild for most people, but it can have catastrophic consequences for an unborn baby if the
mother contracts rubella in the first 16 weeks of pregnancy. If this occurs, the baby is at risk of severe and
permanent birth defects or death. For this reason, pregnant women should have a blood test to check whether
they have already had rubella (and therefore are immune), or not (in which case they should avoid contact with
anyone who has rubella).
Non-immune mothers should not be vaccinated during their pregnancy, but should receive the vaccination after
giving birth (and should then avoid another pregnancy for 28 days).
For more information see the Rubella fact sheet.
Glucose test for gestational diabetes
Some women develop temporary diabetes during pregnancy. This is called ‘gestational diabetes’.
Most women are diagnosed using a pathology test, which requires a blood sample to be taken before and after a
glucose drink. These tests are usually performed between 26 and 28 weeks into the pregnancy.
For more information see the Diabetes – gestational fact sheet.
Immunisations in pregnancy
The seasonal influenza vaccine (often called the ‘flu shot’) is recommended and funded for all pregnant women
under the National Immunisation Program. The flu shot is safe at all stages of pregnancy and provides protection
for you and your baby for the first six months of their life.
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The adult dTpa (diphtheria – tetanus- acellular pertussis) vaccine is also recommended for pregnant women in their
third trimester of pregnancy. This protects both the mother and her baby against pertussis or ‘whooping cough’. A
dose is also recommended for other adult family members and carers of infants less than six months old. This
should be given at least two weeks before these people have contact with the newborn baby. (1)
Routine screening tests in pregnancy
Routine screening tests during pregnancy include:
maternal serum screening
nuchal translucency scan
non-invasive prenatal testing
ultrasound.
Maternal serum screening
The maternal serum screening (MSS) test is a blood test that may be done at:
9 to 13 weeks (first trimester) – when it measures the levels of 2 proteins in the mother’s blood. In
combination with the results of the nuchal translucency test and the mother’s age this is used to screen for
Down syndrome and other genetic conditions (this is known as combined first trimester screening)
14 to 20 weeks + 6 days gestation (second trimester) – when it measures the levels of 4 proteins in the
mother’s blood which, in combination with the mother’s age, is used to screen for genetic conditions (including
Down syndrome) and neural tube defects (such as spina bifida).
For more information see the Maternal serum screening fact sheet.
Nuchal translucency
An ultrasound scan at 11–13 weeks can be used to take a measurement of the amount of fluid in the skin at the
back of the baby’s neck. This measurement is called the nuchal translucency and, in combination with the mother’s
age and the results of the MSS, it can provide an indication of the likelihood of your baby having Down syndrome
or Edwards syndrome.
For more information see the Maternal serum screening fact sheet.
Non-invasive prenatal testing
Non-invasive prenatal testing (NIPT) is also known as ‘cell-free DNA screening’. It looks at the baby’s cell-free DNA
circulating in the mother’s blood to screen for genetic conditions such as Down syndrome, Edwards syndrome and
trisomy 13. This test can be done at any time from 10 weeks gestation. It is more accurate than combined first
trimester screening, or second trimester MSS screening, but it is also more expensive.
Ultrasound
Ultrasound is used during the first trimester of pregnancy (usually at 11 to 13 weeks) to:
check that the baby is developing in the womb – that it is not an ectopic pregnancy
confirm the number of embryos
calculate the due date
perform the nuchal translucency test.
Ultrasound is used during the second trimester of pregnancy (usually at 18 to 20 weeks) to:
check the baby's development
help pick up any abnormalities
determine the sex of the baby, if possible, if you wish to know.
Ultrasound is used during the third trimester of pregnancy to:
check the baby’s growth
check the position of the placenta.
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Ultrasounds do not give completely accurate information. However, they do provide good information and are
painless and safe. Ultrasounds may be on the stomach (‘transabdominal’) or in the vagina (‘vaginal’).
For more information see the Pregnancy tests – ultrasound fact sheet.
Diagnostic tests in pregnancy
If screening tests have suggested that it is likely that your baby has a health condition, you might decide to have
medical tests to confirm the presence or absence of that condition. These are known as diagnostic tests.
Amniocentesis and chorionic villus sampling are both examples of diagnostic tests used during pregnancy.
Amniocentesis
Amniocentesis is only performed on women thought to be at higher risk of delivering a child with a birth defect.
Amniocentesis is a test that may be done during pregnancy (more safely after 15 weeks) to check for foetal
abnormalities (birth defects) such as Down syndrome, cystic fibrosis or spina bifida. A thin needle is used to take a
small amount of amniotic fluid from the sac in the uterus surrounding a foetus. Possible risks include infection or
injury to the baby. There is also a very small risk of amniocentesis causing a miscarriage (1 in every 200-400).
For more information see the Pregnancy tests – amniocentesis fact sheet.
Chorionic villus sampling
Chorionic villus sampling (CVS) is a test that may be done during pregnancy (more safely from 11 to 14 weeks) to
check the baby for some genetic abnormalities such as Down syndrome or cystic fibrosis. A doctor takes a small
sample of the placenta via needle and it is examined in a laboratory. CVS carries a small risk of miscarriage (1 in
every 100-200).
For more information see the Pregnancy tests – chorionic villus sampling fact sheet.
Where to get help
Your doctor
Midwife
Obstetrician
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