Neural tube defects
8-minute read
Key facts
- The neural tube is formed early on in your pregnancy by cells coming together to create a tube-shaped structure that will become your brain and spinal cord.
- Neural tube defects occur when the neural tube does not fully fuse (close).
- You can significantly reduce your baby's risk of having a neural tube defect by taking a folic acid (vitamin B9) supplement while planning and during the first 3 months of your pregnancy.
- Regular ultrasounds and the second-trimester pregnancy serum screening test may help diagnose neural tube defects during pregnancy.
- If your baby has been diagnosed with a neural tube defect during pregnancy, you may see a specialist medical team for more tests and counselling.
What is the neural tube?
The neural tube forms early in your pregnancy when cells fuse together to create a tube-shaped structure. This happens within the first 4 weeks of pregnancy, often before you know you are pregnant. The neural tube grows to eventually become your baby's brain and spinal cord.
What are neural tube defects?
Neural tube defects happen when the neural tube does not fully fuse (close), causing problems with your baby's spinal cord and brain, which include one of the following:
- Anencephaly happens when major parts of the brain, skull and scalp do not develop. Anencephaly is a serious birth defect. Some babies with anencephaly die before or soon after birth.
- Encephalocele is the bulging of brain tissue or its covering membranes through a defect in the skull.
- Spina bifida is when lower parts of the neural tube do not fully close, affecting the development of the spine. The vertebrae (bones of the spine) that cover the spinal cord have one or more openings. Nerve tissues may be exposed. People with spina bifida are affected by nerve damage, which could be mild or severe, depending on the level of damage.
Read more about spina bifida.
What causes neural tube defects?
The exact cause of neural tube defects is not fully known, but there are several genetic and environmental factors that can increase the risk of your baby developing one, including:
- not having enough folic acid in your diet in early pregnancy
- some medicines, such as epilepsy medicines
- having insulin-dependent diabetes
- a family history of or a previous pregnancy affected by a neural tube defect
How are neural tube defects diagnosed?
Neural tube defects are usually diagnosed during the second trimester of your pregnancy with one of the following screening tests:
- Maternal serum screening test: your doctor will offer you have a blood test during weeks 14 to 20. This blood test estimates the chance your baby may have a neural tube defect, and identifies if they are at a higher or lower risk of being born with this problem. On its own, this blood test can't diagnose your baby with a neural tube defect. If the screening test results suggest your baby is at high risk, your doctor may recommend you have more tests.
- Ultrasound screening: your doctor will offer you an ultrasound around weeks 18 to 20. Ultrasounds are used to track your baby's growth and development and can diagnose most cases of neural tube defects.
If a neural tube defect is very mild, it may only be found and diagnosed after your baby is born.
What will happen if my baby has a neural tube defect?
If your baby is diagnosed with a neural tube defect during pregnancy, you and your partner will be referred to a specialised medical team for more tests, information and counselling.
Your healthcare professionals can explain to you how the neural tube defects may affect your baby and what treatment options are available. Often children with neural tube defects will need ongoing support and treatment as they grow. They will need different supports at different stages of growth and development. How much support your child will need will depend on how severe their condition is.
Children with neural tube defects will usually have problems with their brain and spinal cord. Some examples can include:
- physical disability, for example, difficulties with movement
- toileting challenges, for example, not being able to control their bladder and bowel
- difficulties with hearing and vision
- intellectual disability
- differences in physical appearance
You and your partner may wish to discuss with the medical team whether to continue with your pregnancy. Your healthcare team are there to support you and provide relevant information to help you make this very personal decision.
Can neural tube defects be prevented?
You can significantly reduce the chances of your baby having a neural tube defect by having enough folic acid (also known as folate or vitamin B9) before and during your pregnancy. Folic acid supplements can reduce the risk of your baby developing a neural tube defects by 70%.
You can buy folic acid supplements in tablet form at your local health food shop, pharmacy or supermarket.
Folate is also naturally found in:
- green leafy vegetables
- some fruits
- some legumes — beans, peas, lentils
- wholegrain breads
- cereals
Since 2009, folate must be added to all flour used to make bread in Australia.
Read more on folate and pregnancy.
How much folic acid do I need?
The amount of folic acid you need depends on your situation:
- Adults should have at least 0.4mg of folic acid every day.
- If you're planning a pregnancy and for the first 3 months of your pregnancy, you should take an extra folic acid supplement of 0.4mg daily.
- If you are at a higher risk of having a baby with a neural tube defect, it's recommended to take a higher dose supplement (5mg).
Your healthcare professional or dietitian can advise whether you are getting enough folate, and if you are in a high risk group.
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Resources and support
- If you are pregnant and are feeling overwhelmed or want to seek support during your pregnancy, you can reach out to the PANDA helpline at 1300 726 306.
- Learn more about eating folate when you are planning a pregnancy or already pregnant at Healthy Western Australia's Folate and pregnancy page.
- Read the NSW Health guide to Pregnancy supplements.
- If you are concerned about the costs of caring for a child with disability, there's support and payments available to help you. Visit the Services Australia page on Caring for a child with disability.
Looking for information for Aboriginal and/or Torres Strait Islander people?
Read the Family Planning Australia page Yarning About Pregnancy Options, or call the Family Planning NSW Talkline on 1300 658 886.
Visit the First Peoples Disability Network to explore options about rising a child with a disability.
Speak to a maternal child health nurse
Call Pregnancy, Birth and Baby to speak to a maternal child health nurse on 1800 882 436 or video call. Available 7am to midnight (AET), 7 days a week.
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Last reviewed: February 2024