Spina bifida is a type of malformation that occurs during early fetal development. It's known as a type of neural tube defect (NTD), in which either the brain and spine or only the spine fails to develop properly in the womb. There are three types of spina bifida, which vary according to the severity of the malformation:
- myelomeningocele: the most severe form; both the spinal cord and its lining (the meninges) protrude from an opening in the spine
- meningocele: only the lining protrudes
- spina bifida occulta: the mildest form; there is a breach in the spinal vertebrae but it's covered by skin
These malformations are usually in the lower back or at the level of the hips.
In Canada, about 260 babies are born each year with a NTD, and spina bifida is the most common.