Spina bifida | |
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Illustration of a child with spina bifida | |
Specialty | Pediatrics, neurosurgery, rehabilitation medicine |
Symptoms | Hairy patch, dimple, dark spot, swelling on the lower back[1] |
Complications | Poor ability to walk, problems with bladder or bowel control, hydrocephalus, tethered spinal cord, latex allergy[2] |
Causes | Genetic and environmental factors[3] |
Risk factors | Lack of folate during pregnancy, certain antiseizure medications, obesity, poorly controlled diabetes[3][4] |
Diagnostic method | Amniocentesis, medical imaging[5] |
Prevention | Folate supplementation[3] |
Treatment | Surgery[6] |
Frequency | 15% (occulta), 0.1–5 per 1000 births (others)[7][8] |
Spina bifida /ˌspaɪnə ˈbɪfɪdə/[9] (Latin for 'split spine'; SB[10]) is a birth defect in which there is incomplete closing of the spine and the membranes around the spinal cord during early development in pregnancy.[1] There are three main types: spina bifida occulta, meningocele and myelomeningocele.[1] Meningocele and myelomeningocele may be grouped as spina bifida cystica.[11] The most common location is the lower back, but in rare cases it may be in the middle back or neck.[12]
Occulta has no or only mild signs, which may include a hairy patch, dimple, dark spot or swelling on the back at the site of the gap in the spine.[5][1] Meningocele typically causes mild problems, with a sac of fluid present at the gap in the spine.[1] Myelomeningocele, also known as open spina bifida, is the most severe form.[2] Problems associated with this form include poor ability to walk, impaired bladder or bowel control, accumulation of fluid in the brain (hydrocephalus), a tethered spinal cord and latex allergy.[2] Learning problems are relatively uncommon.[2]
Spina bifida is believed to be due to a combination of genetic and environmental factors.[3] After having one child with the condition, or if one of the parents has the condition, there is a 4% chance that the next child will also be affected.[4] Not having enough folate (vitamin B9) in the diet before and during pregnancy also plays a significant role.[3] Other risk factors include certain antiseizure medications, obesity and poorly controlled diabetes.[4] Diagnosis may occur either before or after a child is born.[5] Before birth, if a blood test or amniocentesis finds a high level of alpha-fetoprotein (AFP), there is a higher risk of spina bifida.[5] Ultrasound examination may also detect the problem. Medical imaging can confirm the diagnosis after birth.[5] Spina bifida is a type of neural tube defect related to but distinct from other types such as anencephaly and encephalocele.[13]
Most cases of spina bifida can be prevented if the mother gets enough folate before and during pregnancy.[3] Adding folic acid to flour has been found to be effective for most women.[14] Open spina bifida can be surgically closed before or after birth.[6] A shunt may be needed in those with hydrocephalus, and a tethered spinal cord may be surgically repaired.[6] Devices to help with movement such as crutches or wheelchairs may be useful.[6] Urinary catheterization may also be needed.[6]
Rates of other types of spina bifida vary significantly by country, from 0.1 to 5 per 1,000 births.[15] On average, in developed countries, including the United States, it occurs in about 0.4 per 1,000 births.[7][4][16] In India, it affects about 1.9 per 1,000 births.[17] Europeans are at higher risk compared to Africans.[18]