The most common types of neural tube defects are Anencephaly and Spina Bifida. Anencephaly is the most serious as the baby's brain is not developed properly and the babies do not survive. Spina bifida refers to an opening on the baby's spine that exposes the spinal cord and can cause paralysis and other problems. In Australia, neural tube defects occur in about 1 in 800 babies.

Neural Tube Defects occur early in pregnancy, within the first 28 days of the baby’s development. The backbone begins to form just 21 days after conception. This process occurs along the midline, as the spinal cord fuses together. This fusion theoretically occurs at multiple points along this midline, almost like a zipper, closing the gap from top to bottom. It takes only one week for the backbone to close completely close.

The risk for having a baby with a type of neural tube defect may be increased if there is a close family history of neural tube defects, if the woman has insulin-dependent diabetes or is taking specific medicine to control seizures (epilepsy). Genetic counselling is recommended in these cases.

NTDs have both genetic and environmental factors working together to cause the birth defect. Most people with NTDs are born into a family with no other close relatives with the same condition.

Folic acid (Vitamin B12) acts in helping the neural tube to properly close. Women trying to conceive should take Folic acid (0.5 mg) daily for 3 months prior to and for the first 4 months of their pregnancy. A higher dose of folic acid (5 mg) is recommended for prevention for women who have already had a baby with an NTD.