1902
Include spina bifida, anencephaly, craniorachischisis and encephalocele.
Failure of the rostral neuropore closure leads to anencephaly.
Occurs within the first four weeks of conception when the neural tube in the embryo does not close properly, resulting in the fetus developing spina bifida, anencephaly, or encephalocele, depending on where the lesion occurs, and how large it is.
Approximately 1 per 1000 births in the U.S.
Neural tube defects, occur in about 3,000 pregnancies each year in the United States.
Spina bifida is the most common of this type of birth defect.
Quarter million pregnancies world-wide result in an infant with a neural-tube defect or an abortion performed because of such a defect.
A woman with one fetus with this defect is at increased risk in subsequent pregnancies.
Folic acid supplementation decreases the risk by 80%.
Folic acid supplements to prevent neural tube defects starting before pregnancy.
Starting folic acid after the pregnancy is too late to miss the preventive opportunity.
Most women do not take folic acid supplements before pregnancy.
Most pregnant women carrying a fetus with a neural-tube defect do not have folic acid deficiency.
Causes include antifolate drugs, anti-seizure medications, chromosome abnormalities and environmental factors.
Risks include previously affected child, inadequate maternal folic acid intake, diabetes, use of anticonvulsants carbamazepine or valproic acid, obesity or B12 deficiency.
Some women with a neural tube defect pregnancy have autoantibodies to folate receptors.
Closing normally occurs around 24 days after conception, usually before a woman realizes that she is pregnant.
Prevalence higher among Hispanic women than women of other racial/ethnic populations.
USPSTF recommends that all person plan to, or could become pregnant take a daily supplement of .4 to .8 mg of folic acid, because of the high certainty of substantial net benefit.