Spina Bifida

Causes

Doctors are not sure why neural tubes do not develop or close properly in some babies. While spina bifida appears to occur in certain families, it follows no particular law of inheritance. Ninety-five percent of babies with spina bifida and other neural tube disorders are born to parents with no family history of these disorders.

Often, spina bifida is present in babies born with fetal alcohol syndrome. Women who drink large amounts of alcohol during their pregnancy have an increased risk of giving birth to a child with physical and mental problems due to alcohol exposure.

Risk Factors

A few factors have been identified that increase the risk of spina bifida and other neural tube defects:

• Presence of a neural tube defect in a previous child
  Couples who have had one child with a neural tube defect have a 1 in 40 chance of having another baby with the same defect. That risk increases to 1 in 20 if two previous children have been affected by the condition. A woman who was born with a neural tube defect, or has a close relative with one, has a greater chance of giving birth to a child with spina bifida.

• Lack of folic acid
  This vitamin is important to the healthy development of a fetus. Lack of folic acid increases the risk of spina bifida and other neural tube defects.

• Some medications
  Certain drugs prescribed for seizures, such as valproic acid or carbamazepine, increase the risk of spina bifida, perhaps because they interfere with the body's ability to use folic acid.

• Diabetes
  The risk of spina bifida increases with diabetes, especially when the mother's blood sugar is elevated early in the pregnancy. Much of this risk is preventable by careful blood sugar control and management.

• The mother's age
  Spina bifida is more commonly seen in children of teenage mothers.

• History of miscarriage

• Birth order
  Firstborn infants are at higher risk.