Preventing Neural Tube Defects

Neural tube defects (or NTDs) happen when the spine and brain do not develop completely while the fetus is forming in the uterus. At the beginning of pregnancy, the brain and spinal cord start out flat and then roll up into a long tube. This "neural tube" grows to become the brain and spinal cord. If the tube does not close all the way, any part that is still open becomes a birth defect. NTDs vary in severity. Some NTDs can be mild with no or few symptoms while others can be fatal. The exact cause of NTDs is not known, but a B vitamin called folate (or folic acid) may help if taken just before pregnancy and during the first few weeks. Folic acid is available in higher doses by prescription from a doctor. It is also found in regular daily multivitamin tablets, prenatal vitamins, and in certain foods.

Introduction

Neural tube defects (or NTDs) happen when the spine and brain do not develop completely while the fetus is forming in the uterus. At the beginning of pregnancy, the brain and spinal cord start out flat and then roll up into a long tube. This “neural tube” grows to become the brain and spinal cord. If the tube does not close all the way, any part that is still open becomes a birth defect. This health education tutorial explains what neural tube defects are. It also discusses how women who have had pregnancies with neural tube defects can use folic acid to prevent these defects in the future.

Neural Tube Defects

Some examples of NTDs are spina bifida, anencephaly, and encephalocele. NTDs vary in severity. Some NTDs, such as spina bifida, can be mild with no or few symptoms. Other NTDs, such as anencephaly, can be fatal. Certain seizure medicines can cause NTD. Sometimes NTDs run in families, or they may be part of a genetic disease.

Prevention

The exact cause of NTDs is not known, but a B vitamin called folate (or folic acid) may help if taken just before pregnancy and during the first few weeks. New research shows that mothers who take folic acid three months before and during the first three months of pregnancy can reduce the chance of having another NTD pregnancy. Some developing babies seem to have a high need for this vitamin, so it is important for women who have already had a child with any NTD to take extra folic acid. Folic acid is available in higher doses by prescription from a doctor. It is also found in regular daily multivitamin tablets, prenatal vitamins, and in certain foods.

Women who have had a previous NTD pregnancy should take 4 milligrams (4mg) every day when trying to become pregnant. See your doctor to get a prescription for the right amount. It is not safe to take several multivitamin pills daily to obtain the correct amount. Extra doses of other vitamins might be harmful. If you are using birth control and do not plan to get pregnant, it is still important to take a lower dose (0.4 mg) of folic acid.

New Pregnancy

It is important for mothers who have had NTD pregnancies to plan ahead and start taking folic acid if they want to have another baby. This is because the neural tube closes before most women know they are pregnant. The chance of having another NTD pregnancy is usually about 2 - 4% or between 1 in 30 and 1 in 50. For most women, but not all, the risk is reduced by two thirds by taking the recommended amount of folic acid before and during pregnancy.

Conclusion

If you had a baby with a neural tube defect and are planning another pregnancy, remember the following 4 points:

1. Use an effective method of birth control until you decide to get pregnant.

2. Talk to your health care provider before you stop using birth control and ask for a prescription for folic acid vitamin supplements.

3. Start taking your folic acid prescription before you get pregnant.

4. Once you are pregnant continue to take folic acid every day until your health care provider says you should stop.