Causes
The exact cause of spina bifida is still unknown. Something goes wrong in the first 2 months after conception but experts don't often know why. It's been shown that women who have low levels of folic acid (a B vitamin) are more likely to give birth to children with neural tube defects. The assumption is that when the genes of the fetus give the order to construct the spine, the necessary chemical building blocks are missing.
There's almost certainly no single spina bifida gene, and it can occur in any pregnancy, yet some people are predisposed to it. Women with a family history of neural tube defects are at increased risk of giving birth to a baby with such a defect. Couples who already have one child with spina bifida have a slightly higher risk of having another baby with neural tube defects.
Still, most cases of spina bifida occur in families with no history of the condition.
Other risk factors for having a child with spina bifida include obesity and uncontrolled diabetes.