Spina bifida

Spina bifida describes birth defects caused by an incomplete closure of one or more vertebral arches of the spine, resulting in malformations of the spinal cord. The spinal membranes and spinal cord may protrude through the absence of vertebral arches (called a cleft). These malformations fall into three categories: spina bifida occulta, spina bifida cystica (myelomeningocele) and meningocele.

Causes

Spina bifida is caused by the failure of the neural tube to close during embryonic development. Normally the closure of the neural tube occurs around the thirtieth day after fertilization. However, if something interferes and the tube fails to close properly, a neural tube defect will occur. Neural tube defects include the conditions of anencephaly, encephalocele, and spina bifida.

Related Topics:
Neural tube - Embryonic - Fertilization - Anencephaly - Encephalocele

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Spina bifida occurs in the first month of pregnancy, often before the woman knows that she is pregnant.

Related Topics:
Pregnancy - Woman

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Spina bifida does not follow direct patterns of heredity like muscular dystrophy or haemophilia. Studies show that a woman who has had one child with a neural tube defects such as spina bifida, have about a 3% risk to have another child with a neural tube defect. This risk can be reduced to about 1% if the woman takes high doses of (4mg/day) folic acid before and during pregnancy.

Related Topics:
Heredity - Muscular dystrophy - Haemophilia - Neural tube defect - Folic acid

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It is known that women taking certain medication for epilepsy and women with insulin dependant diabetes have a higher chance of having a child with a neural tube defect. It is also more common among those of Gaelic descent than any other ethnic group.

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