For most parents, pregnancy ends with the birth of a normal healthy baby. In a small amount of pregnancies the baby develops with a serious problem.
If you have a history of any abnormalities in your family, a history of recurrent miscarriages or that you are a known carrier of a genetic condition, you should consider genetic counselling to find out your chances of having an affected baby.
Neural tube defects, Down syndrome and trisomy 18 are serious abnormalities that occur early in the development of a baby. It is not known why they happen.
Screening tests involve blood tests from the mother and ultrasounds to work out if your baby is at an increased risk of one of the following conditions:
If the screening is positive or the markers are high, you may receive a diagnostic test such as chorionic villus sampling or an amniocentesis. The risk of miscarriage is around 1% for both of these procedures.
Genetic screening tests are not compulsory. Before deciding if you want these tests, you should understand what the abnormalities are, what the tests can tell you and what the results can mean for you and your family.
Your doctor will give you information about genetic screening tests and pregnancy, but it is your decision to have the tests.
Genetic screening blood tests include:
- harmony - through Healthscope Pathology
- verifi - through Sullivan Nicolaides Pathology.
Blood tests and ultrasounds are conducted in the NT by the South Australian Maternal Antenatal Screening program.
Your general practitioner (GP) can give you a referral for these tests and tell you about any costs and how long it takes to get your results.
If you do decide to have tests, a high risk screen will likely be followed up with an amniocentesis to confirm any issues.
Amniocentesis tests your pregnancy for chromosomal abnormalities like Down syndrome. It involves taking a small sample of the fluid surrounding your baby through a needle in your abdomen. The needle does not touch your baby.
For more information about amniocentesis, download the Royal Women's Hospital's amniocentesis fact sheet.
Chorionic villus sampling
Chorionic villus sampling tests your pregnancy for genetic abnormalities. It involves taking a sample of the developing placenta transvaginally.
For more information about chorionic villus sampling, download the Royal Women's Hospital's chorionic villus sampling fact sheet.
To find out more about genetic tests and genetic counselling in the Northern Territory, contact the NT Clinical Genetics Service:
Royal Darwin Hospital
PO Box 41326
Casuarina NT 0811
Phone: (08) 8944 8731
Fax: (08) 8922 8463
For Aboriginal women
The Menzies School of Health Research has more information about genetic screening in pregnancy for Aboriginal women. This information was developed in consultation with Yolngu women in Galiwin'ku.