Neural Tube Defects
are birth defects of the brain, spine, or spinal cord. They happen in
the first month of pregnancy, often before a woman even knows that she
is pregnant. The two most common neural tube defects are spina bifida
and anencephaly. In spina bifida, the fetal spinal column doesn't close
completely. There is usually nerve damage that causes at least some
paralysis of the legs. In anencephaly, most of the brain and skull do
not develop. Babies with anencephaly are either stillborn or die shortly
after birth.