06 Jun Spina Bifida Explained

Spina bifida comes from the term for ‘split spine’ in Latin. It is a serious birth defect that involves damage to the spine and to the nervous tissue of the spinal cord.

In people affected with spina bifida, some of the vertebrae of the spine don’t close properly during development. The spinal cord’s nerves also don’t develop normally, and are exposed through the gap in the spinal column and therefore susceptible to further damage. Nerve signals to most parts of the body located below the level of the ‘split spine’ are damaged and a wide range of muscles, organs and bodily functions are affected.

Spina bifida can occur at any place along the spine. However, surviving babies are generally affected lower down the spine because at higher points, the survival rate is low. Generally, defects higher on the spine produce a greater risk of paralysis and other debilitating complications.

The effects of spina bifida vary according to the type, location and severity of the condition.

Complications of spina bifida

People are affected in a variety of ways, ranging from minor to severe, typically including:

• a range of walking difficulties, a degree of paralysis, reduced sensation and proneness to burns and pressure sores in the lower body, legs and feet;
• abnormal joints;
• deformities of the spine, commonly scoliosis, in which the spine bends into an S shape;
• a condition known as ‘cord tethering’, in which the spinal cord ‘sticks’ to the area of the original lesion and becomes stretched;
• degrees and types of urinary and faecal bowel incontinence;
• increased stress on the kidneys;
• some level of sexual dysfunction, particularly for men; and
• learning difficulties.

In most cases, the baby has hydrocephalus (a build-up of cerebrospinal fluid in the brain) and a condition known as the Arnold Chiari malformation, in which the brain stem physically ‘jams into’ the spinal cord. These abnormalities may cause many different brain-function disabilities.

The Risk

The risk of spina bifida is approximately one in every 1,000 pregnancies. It is caused by a combination of genetic and environmental factors that are not yet fully understood. Inadequate metabolism of the vitamin folate in early pregnancy is a significant factor. Taking folate one month before conception and during the first three months of pregnancy can prevent up to 70 per cent of spina bifida cases.

Detection

More than 90 per cent of cases of spina bifida should be detected with a good-quality ultrasound at 18 weeks. If present, specialist gynaecological care is provided until birth. The number of babies born with spina bifida has dropped dramatically in recent years due to improved ultrasounds and other tests detecting the condition and providing the option of pregnancy termination.

If first detected at birth, the baby has a large soft lump or lesion on their back. This lump contains spinal cord nerves and tissue. Exposed nerves must be surgically placed gently back under the skin within 24 hours.

Treatment options

There is no cure for spina bifida. Treatment options include:

• surgery to close the lesion and reduce the risk of infection;
• the insertion of a tube, called a shunt, into the ventricles in the brain where the spinal fluid is produced, to allow the excess cerebrospinal fluid to drain out;
• surgery of the legs and feet to improve mobility;
• walking aids or wheelchairs;
• diet and enemas to manage faecal incontinence;
• surgery to increase bladder size and tighten muscles;
• self-catheterisation and continence pads to manage urinary incontinence;
• faecal or urinary bags if required; and
• regular monitoring of kidney, bladder, shunt and spine functions.

The importance of folate

Folate (folic acid) is a B-group vitamin. The recommended dose of folate, taken one month before conception and during the first three months of pregnancy, can prevent the occurrence of up to 70 per cent of neural tube defects. The National Health and Medical Research Council recommends that all women planning a pregnancy or likely to become pregnant should be offered folic acid supplements, with women in the high-risk category needing a higher dose.

High-risk groups include:

• those with a previous child with a neural tube defect;
• those with a family history of NTDs on one or both sides;
• those with a close relative with an NTD;
• those with a close relative with a child with an NTD; and
• women taking certain anti-epileptic medications.

See your doctor for specific advice regarding your own circumstances and medical history.

Good sources of folate include:

• folate supplements;
• foods naturally rich in folate, such as asparagus, spinach, oranges, bananas and legumes; and
• foods fortified with folate, such as some breakfast cereals and bread. Check the nutrition information on the packaging for the folate content of packaged foods.