Spina bifida is when a baby's spine and spinal cord don't develop properly in the womb, causing a gap in the spine.
Spina bifida is a type of neural tube defect. The neural tube is the structure that eventually develops into the baby's brain and spinal cord.
The neural tube starts to form in early pregnancy and closes about four weeks after conception.
In spina bifida, part of the neural tube doesn't develop or close properly, leading to defects in the spinal cord and bones of the spine (vertebrae).
It's not known what causes spina bifida, but a lack of folic acid before and in the early stages of pregnancy is a significant risk factor.
Types of Spina Bifida
There are several different types of spina bifida, including:
- Myelomeningocele – is the most severe type of spina bifida; the baby's spinal canal remains open along several vertebrae in the back, allowing the spinal cord and protective membranes around it to push out and form a sac in the baby's back.
- Meningocele – is another serious type of spina bifida where the protective membranes around the spinal cord (meninges) push out through the spine; the spinal cord usually develops normally so surgery can often be used to remove the membranes without damaging the nerves.
- Spina Bifida Occulta – is the most common and mildest type of spina bifida; one or more vertebrae don't form properly but the gap in the spine is very small; spina bifida occulta doesn't usually cause any problems and most people are unaware that they have it.
These pages focus on myelomeningocele, the most severe type of spina bifida and this is the type referred to whenever the term spina bifida is used.
Shine is a charity that provides help and support for people affected by spina bifida. Shine's website has more information about the other types of spina bifida.