Neural Tube Defects

A neural tube defect (NTD) is a birth defect of the brain or spinal cord. The neural tube is the embryonic structure that grows into the brain and spinal cord. The neural tube starts out as a small ribbon of tissue that normally folds inward to form a tube by the 28th day after conception. NTDs can result when the neural tube does not develop properly.

The most common NTDs are spina bifida and anencephaly. Spina bifida occurs when the spine or spinal cord does not completely form. This birth defect can cause paralysis of the lower body, problems with bowel or bladder control, and learning disabilities. There are varying degrees of spina bifida and most babies born with this birth defect live. Anencephaly occurs when the brain and skull do not completely form. This condition is always fatal.

The mechanism by which folic acid prevents NTDs is not well understood and is the topic of current research. In the U.S., an estimated 2,500 babies are born with NTDs each year and many additional affected pregnancies result in miscarriage or stillbirth.

Fast Facts About Folic Acid and Neural Tube Defects (NTD)

All women and men 14 years old and older should consume 400 micrograms (mcg) of folic acid every day.
Taking folic acid daily before pregnancy and during the first few weeks of pregnancy can reduce your chance of having a baby with an NTD (such as spina bifida or anencephaly) by 50 to 70%.
Any woman capable of becoming pregnant could have an NTD-affected pregnancy. In fact, 95% of NTDs occur in women who have never had an NTD-affected pregnancy.
NTDs occur within the first four weeks after conception - before most women know they are pregnant. In addition, 50% of all pregnancies in the U.S. are not planned. Therefore, women should consume 400 mcg of folic acid every day, whether or not they are planning a pregnancy.
Only one third of American women consume the recommended amount of folic acid in their diet every day.
Folic acid may also reduce your risk of heart disease, stroke, colon and cervical cancer, and other birth defects such as cleft lip and palate.

Content provided by the Family, Maternal & Child Health (FMCH) Programs of Contra Costa Public Health Division. For more information, call 925-313-6254.