Please note: The information on this page is general and in no way replaces consultation with a health professional. Whereas every effort is made to ensure accuracy and relevance this in no way replaces seeing a Health Professional.
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Please Contact Us to help us assist you.
Antenatal / Prenatal testing is available to check the health of your baby. It is your choice if you decide to have these tests and you should discuss your options with Dr. Petrina, your chosen health care provider or a genetic counsellor.
Nuchal Translucency Scan
A nuchal translucency scan is part of the ultrasound scan that most pregnant women have at around 12 weeks of pregnancy. If you decide to have the scan, the health professional performing the ultrasound will measure the size of the nuchal fold at the back of your baby’s neck.
The results of a nuchal translucency scan may tell you if your baby has a high or low risk of a chromosomal abnormality.
Chromosomal abnormalities include trisomy 21 (Down Syndrome), trisomy 18 (Edwards Syndrome) or trisomy 13 (Patau syndrome)
The scan looks at and measures the thickness of your baby’s nuchal fold, a fluid-filled sac on the back of your baby’s neck. Increased thickness might indicate a chromosomal abnormality, but it doesn’t tell you that your baby definitely has, or doesn’t have, an abnormality. It is important that all who have a Nuchal Screen test that they are aware that the results will tell you if your baby is at high risk or low risk of chromosomal abnormality in comparison to other women with similar age and demographics as yourself.
Dr Petrina will discuss your options and help you to decide if you would like to have a more invasive diagnostic test, such as chorionic villus sampling (CVS) or amniocentesis. These diagnostic tests can tell you definitively if your baby has a chromosomal abnormality or not.
Morphology / Anomaly Scan
The anomaly scan is a detailed ultrasound scan that looks at your baby’s body and observes the position of the placenta, the umbilical cord, the amniotic fluid around your baby, and your uterus and your cervix. It is also known as a ‘morphology scan’ or a ‘20 week scan’. It has been incorrectly known as a gender scan, although the sonographer can often tell if you are having a boy or a girl with about 95% accuracy, this is not the main reason for the scan. Let the Ultrasonographer know if you want to know the gender or not.
The sonographer will check to see if your baby has any abnormalities in their growth or development, including in their heart, stomach, kidneys and limbs. It is important to know that while many abnormalities are picked up by this scan, not all of them are.
If your placenta is positioned low in your uterus, Dr. Petrina or your health professional will tell you that you have a low lying placenta, also known as placenta praevia. A low lying placenta at 18-20 weeks does not necessarily mean that it will be low at the time of birth, so there is no cause for concern. Another ultrasound is recommended in the third trimester, to check that your placenta has relatively moved away from your cervix made possible by the development of the lower segment.
If your placenta is close to your cervix in the third trimester, there may be an increased risk of bleeding during labour. If this is the case, your doctor or midwife will discuss with you what your options are for the birth.
Chorionic Villi Sampling (CVS)
Chorionic villus sampling (CVS) is a test carried out during pregnancy to detect specific abnormalities in an unborn baby. A sample of cells is taken from the placenta (the organ that links the mother’s blood supply with her unborn baby’s) and tested for genetic defects. More info here
Amniocentesis
Amniocentesis is a diagnostic test carried out during pregnancy, usually during weeks 15-20. It can assess whether the unborn baby (fetus) could develop, or has developed, an abnormality or serious health condition.
Down Syndrome Screening inc NIPT (Harmony or Generation screen)
Down syndrome is a genetic condition – it is not an illness or disease. It occurs at conception as a result of an extra chromosome.
Prenatal tests are divided into two types: Screening tests and Diagnostic tests.
Screening tests
These are tests that can be carried out on the mother’s blood in the first or second trimester of pregnancy. In the first trimester, you would have the blood test as well as an ultrasound that measures nuchal translucency (See above) and also its nasal bone.
There is also a new non-invasive prenatal blood test (NIPT), which is available in the private health system in Australia. While this test is highly accurate, detecting 99% of pregnancies with a diagnosis of Down syndrome, women are usually advised to be sure by also having a CVS or amniocentesis.
NIPT is costly and there is currently at the time of writing no Medicare rebate.
Most pregnant women are also routinely offered an ultrasound at 19-20 weeks of pregnancy, which can sometimes show other
signs of Down syndrome.
The likelihood of your baby having Down syndrome is calculated and if the result shows there is an increased likelihood, you
may be offered a diagnostic procedure such as chorionic villus sampling (CVS) or amniocentesis. Both tests increase the risk of miscarriage
Diagnostic tests
Both CVS and amniocentesis are invasive procedures that involve obtaining a sample of the baby’s genetic material for examination.
Genetic Counselling
Genetic counselling involves talking about a genetic condition with a health professional who has qualifications in both genetics and counselling. Genetic conditions are caused by changes or mistakes in genes. These conditions may be inherited from one or both parents. Genetic counselling aims to help people understand and adapt to the impact that a genetic condition may have on their lives.
If you have an inherited condition, genetic counselling can help you understand more about the condition, what causes it and how you and your family can adjust to it and plan for the future.
Some of the genetic conditions (sometimes referred to as ‘hereditary disorders’) people talk to a genetic counsellor about are:
- cystic fibrosis
- Down syndrome
- Fragile X syndrome
- haemochromatosis
- haemophilia
- Huntington’s disease
- muscular dystrophy
- neural tube defects.
Genetic counselling is different from genetic testing, which involves your doctor doing tests if you have symptoms or a family history of a genetic condition. Genetic testing can tell you about the likelihood and risk of your passing a genetic condition on to any children that you conceive.
You may have diagnostic tests as part of your pregnancy check ups and scans, to find out if your baby has a genetic condition. These tests include amniocentesis and chorionic villus sampling or CVS.
