It’s your choice to have screening tests to check whether your baby may have Down syndrome or some other rare genetic conditions such as Turner syndrome, Trisomy 13 and Trisomy 18.
These conditions happen at the start of pregnancy and can affect your baby’s growth and development. Screening can provide information about the chance or likelihood of your baby having one of these conditions. Other tests are needed to find out for sure if your baby has a condition.
The test
The screening depends on how many weeks pregnant you are.
If you are less than 14 weeks pregnant, this will be a blood test from you and a scan of your baby.
If you are 14–20 weeks pregnant, this will be a blood test only.
The blood test is free; you may be charged for the scan by some ultrasound providers.
The blood test measures certain hormones and proteins in your blood. The results of these tests are then combined with other information, such as your age and weight, to give you a risk result.
Results
Your doctor or midwife will give you your result within 10 days.
Your result will either show increased risk or low risk.
- Low risk – this result means that you have a low chance of having a baby with one of the conditions being screened for.
- Increased risk – this result means that there is an increased chance that you are carrying a baby with Down syndrome or another condition.
Most women in the increased risk group will find out their baby does not have a condition either when they have diagnostic testing or when the baby is born.
If your results show an increased chance, discuss this with your doctor or midwife. They will be able to give you some information as well as helping you to find other organisations and people who can help. Sometimes talking to organisations that help families with children who have conditions such as Down syndrome can help.
Your doctor or midwife will offer to refer you to a specialist obstetrician to further discuss your options for diagnostic testing.
Diagnostic testing
Diagnostic testing is designed to find out for sure whether or not your baby has one of these conditions. If screening shows that there is an increased risk for a genetic condition, you will be offered chorionic villus sampling (taken from the placenta/whenua) or an amniocentesis (taken from the waters around the baby). The type of sample depends on how many weeks pregnant you are.
You can choose whether or not to have diagnostic testing. Some women choose to stop at this point, regardless of an increased risk result, while others want to have diagnostic testing so that they can find out for sure whether their baby has one of the conditions being screened for.
We recommend you talk to your specialist obstetrician about diagnostic testing and the risks before you decide.
In diagnostic testing, a thin needle is inserted through the skin of your abdomen and into the developing placenta/whenua or the fluid around the baby. Samples are sent to a laboratory. This is the only type of testing that can confirm whether or not your baby has one of the genetic conditions before birth.
Amniocentesis and chorionic villus sampling have some risks. For every 200 women who have diagnostic tests, 1 or 2 will have a miscarriage.
Related websites
Antenatal screening and testing for Down syndrome and other conditions – HealthEd
Information for pregnant women to help them make informed decisions about optional screening and testing for Down syndrome and other conditions.
CCS Disability Action
To strengthen communities and provide support so people with disabilities are included in the life of their family and in their community.
Firstport
Information, advice, support or equipment relating to disability in New Zealand.
IHC
A website about living with intellectual disability in New Zealand. IHC New Zealand Inc advocates for the rights, inclusion and welfare of all people with an intellectual disability and support them to live satisfying lives in the community.
Kiwi Families
A website centered on practical parenting advice for parents in New Zealand.
New Zealand Down Syndrome Association
The New Zealand Down Syndrome Association is a family/ whānau driven organisation for people whose lives have been changed by Down syndrome.
New Zealand Federation of Disability Information Centre
The Federation nationally promotes and supports the local provision of generic disability information and referral services that are community integrated, needs driven and focused on achieving the aims of the New Zealand Disability Strategy Document.
New Zealand Organisation for Rare Disorders
Providing information for patients, their family and professionals, and building partnerships to accelerate research towards control and cure of rare disorders.
Disability Connect
Supporting parents and families of disabled children and young people.
