Anencephaly (Neural Tube Defect)
What are the causes and symptoms of anencephaly?
If the neural tube fails to close properly, the developing brain and spinal cord are exposed to the amniotic fluid that surrounds the fetus. This exposure causes the nervous system tissue to break down (degenerate). As a result, people with anencephaly are missing large parts of the brain called the cerebrum and cerebellum.
Spina bifida facts*
*Spina bifida facts medical author: Melissa Stöppler, MD
- Spina bifida is a form of birth defect known as a neural tube defect.
- Spina bifida results from an incomplete formation of the brain, spinal cord, and/or meninges in an infant.
- Spina bifida occurs in 1,500 to 2,000 newborns each year in the U.S.
- While the exact cause of spina bifida is unknown, a deficiency of folic acid in the mother's diet has been linked to its development.
- Spina bifida can vary in severity. Spina bifida occulta is a very mild form of the condition.
- Spins bifida is typically diagnosed prior to birth.
- There is no known cure for spina bifida. Treatment depends on the severity of the condition but typically includes surgery to close the defect and minimize the risk of infection or further trauma within the first few days of life.
- Fetal surgery (performed in utero) is a treatment option for some forms of spina bifida.
- Screening tests include second trimester fetal ultrasound and maternal serum alpha fetoprotein (MSAFP) testing.
Introduction to spina bifida
The human nervous system develops from a small, specialized plate of cells (the neural plate) along the back of an embryo. Early in fetal development, the edges of this plate begin to curl up toward each other, creating the neural tube-a narrow sheath that closes to form the brain and spinal cord of the embryo. As development progresses, the top of the tube becomes the brain and the remainder becomes the spinal cord. This process is usually complete by the 28th day of pregnancy. But if problems occur during this process, the result can be brain disorders called neural tube defects, including spina bifida.