The Facts
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.
The frequency of spina bifida in the United States has been declining gradually since the 1990s. In 1991, the rate was 2.5 per 10,000 total births; in 2004, it was 2.0 per 10,000 total births. This is mainly due to the addition of folic acid to grain products and American mothers taking folic acid supplements while pregnant. There are about 750 spina bifida births each year in the United States.