Meningomyelocele is a type of spina bifida, a kind of birth defect in which the spinal canal and the backbone don’t close before birth. This type of birth defect is also called a neural tube defect. The spinal cord and the meninges (the tissue that covers the spinal cord) may actually protrude through the child’s back.
In some cases skin covers the spinal cord and meninges, in some cases it sticks through the skin.
Spina bifida most commonly occurs in three forms: spina bifida occulta, meningoceles, and meningomyelocele. Of these three, meningomyelocele is the most common.
According to the National Institutes of Health, this condition occurs in about one out of every 800 babies. Meningomyelocele is sometimes called myelomeningocele (NIH).
What Causes Meningomyelocele?
Doctors do not know exactly why this condition occurs. It is thought that a lack of folic acid before and during early pregnancy impairs the development of the spinal cord.
The condition may also be partly genetic. Having one child with this disease makes it more likely that you will have another affected child.
According to the University of Connecticut Health Center, a woman with one affected child has a one in 50 chance of having another baby with the condition.
Compare this to the one in 800 chance for the general population. The University of Connecticut Health Center further reports that a woman with two affected babies has a one in 25 chance of her third child also having the condition (UCHC). In many cases, however, there is no family connection.
What Are the Symptoms of Meningomyelocele?
A baby with meningomyelocele is born with the spinal cord exposed. The baby may have a sac on his or her mid to lower back.
The exact symptoms and their severity depend on your child’s particular case. Unfortunately, this tends to be a severe type of spina bifida, with the spinal cord typically being abnormal.
The affected body parts are those below the location of the problem, specifically the legs, bladder, and bowels.
In some children, these body parts are only mildly affected. Others might have complete loss of control of their bladder and/or bowel. The legs may be partially or completely paralyzed or lack sensation.
Other possible symptoms include:
- orthopedic deformities
- hydrocephalus (buildup of fluid in the skull that leads to swelling of the brain)
- Chiari II malformation (structural defects in the part of the brain that controls balance)
Because the spinal cord is exposed, a child with meningomyelocele is at risk of developing bacterial meningitis.
How Is Meningomyelocele Diagnosed?
This condition is usually diagnosed during the second trimester of pregnancy when women can have a blood test called the quadruple screen.
The test can screen for several conditions including meningomyelocele, Down syndrome and other congenital diseases of the baby. Most women who carry a baby with neural tube defects have elevated levels of maternal alpha fetoprotein (AFP).
If the screen test is positive, further testing including a pregnancy ultrasound and/or amniocentesis can confirm the diagnosis.
How Is Meningomyelocele Treated?
This condition is typically diagnosed during early pregnancy, and some women opt to terminate the pregnancy.
If you choose not to do so, your baby will generally need surgery after birth. Prompt surgery can help protect your child from infections such as meningitis.
Your doctor might prescribe antibiotics as an additional measure in preventing these infections.
If your child has hydrocephalus, sometimes called water on the brain, he or she may need to have a shunt inserted. This shunt can drain the extra liquid from around the brain, reducing pressure on the brain into your child’s abdomen.
Your child may not develop bladder control. If this is the case, he or she might need a catheter to help drain the bladder.
Because of the effect this condition can have on your child’s lower limbs, he or she might need to wear braces, an orthopedic device that support the legs and/or main part of the body.
In most cases, your child’s treatment will be lifelong. He or she will need to be seen regularly to assess any developing problems. He or she may also need to use a wheelchair for life.
Management issues include:
- Infants need referral and transport to a tertiary neonatal centre for assessment by a coordinated team of specialists experienced in dealing with these lesions.
- A treatment policy can be formulated and discussed with the parents.
Before and during transport:
- the lesion, especially if ruptured, should be covered with a sterile non-adherent dressing
- the infant should be nursed in the prone position and the defect protected eg by foam rubber cut into a doughnut
- IV access is required to provide antibiotics eg penicillin and Gentamicin (preferably after blood is taken for culture).
- IV fluids are required if an excessive delay before oral feeds can commence is anticipated, respiratory difficulty or hypoglycaemia is present.
Multidisciplinary follow up is required.
Detection and referral
Some points to note about detection and referral for neural tube defects:
- The detection of neural tube defects frequently occurs before birth as a result of maternal alpha-fetoprotein measurement or ultrasound examination.
- Referral to a multidisciplinary team for family counselling and management plan development is then appropriate.
- Genetics Health Services Victoria provides services throughout Victoria and can be contacted via (03) 8341 6201.
- Occasionally affected infants will deliver unexpectedly.
Prognosis for survival and extent of the disability depends on:
- the level of the lesion
- the degree of involvement of the spinal cord fibres
- presence of infection
- the presence of associated anomalies:
- central nervous system (e. hydrocephalus, Arnold-Chiari malformation)
How Can I Prevent Meningomyelocele?
Because spina bifida and other neural tube defects are believed to be related to low levels of folic acid, it’s important to take folic acid supplements during pregnancy.
Folic acid is a B vitamin that is important in the development of red blood cells and is important for good health in general, especially during pregnancy. Doctors advise taking a folic acid supplement before you become pregnant.