What is Spina Bifida?

My neighbor has a child with spina bifida. What caused this to happen?

Spina bifida is an opening that occurs along the lower end of the developing baby’s spinal column (backbone). Spina bifida, as a form of Neural Tube Defect (NTD), accounts for 50% of these spinal birth defects. Openings can also occur along the upper end of the backbone or even in the skull, and are called anencephaly (45%) and encephalocele (5%). Together, these NTDs are among the most common and serious of birth defects. In South Carolina, 1 out of every 600 babies born has this condition, which is a higher rate than other parts of the country.

Neural tube defects occur early in a pregnancy, within the first 28 days of a baby’s development. The backbone begins to form just 21 days after conception. This process occurs along our midline, as the spinal cord fuses together, from our backbone on over our cranium, to close the skull. This fusion theoretically occurs at multiple points along this midline, almost like multiple zipper sites, closing up the gap from top to bottom. It only takes one week for the backbone to completely close. If something interferes with this normal process of closure, an NTD occurs.

Spina bifida defects can sometimes be quite small, almost pinpoint in size, or much larger openings (grapefruit size). In 5% of cases, the opening is covered with skin, thus making it more difficult to diagnose. The most common problem seen in spina bifida is damage to the nerves as they lay exposed in the developing baby. This damage may cause the baby to have weak or totally paralyzed legs. It also may cause loss of feeling in the legs and loss of bladder/bowel control. If the opening is not skin covered, infection is always a concern, many times requiring immediate surgery. Moreover, blockage can occur in the flow of the spinal fluid at the lesion, leading to a buildup of fluid on the brain ("water in the head"). This excessive fluid and subsequent pressure on the brain can cause further damage, so surgical shunting of the fluid is required.

NTDs have both genetic and environmental factors working together to cause the birth defect. Most people with NTDs are born into a family with no other close relatives with the same condition. Therefore, 95% of the time, it is not inherited. Pregnancy tests (maternal serum screen, focused ultrasound, amniocentesis) are all helpful tools in identifying babies with NTDs. Prevention of this serious birth defect is also becoming a reality.

Recent studies suggest that folic acid, vitamin B-12, acts in helping the neural tube to properly close and ensure a healthy pregnancy. We recommend that all women of childbearing age, especially if trying to conceive, take a daily multivitamin with folic acid for 3 months prior to conception. Once you become pregnant, continue on with your prenatal vitamins. A higher dose of folic acid is recommended for prevention in couples that already have had a baby with a NTD. For further information regarding NTDs and prevention, please call 1-800-6SOMEDAY.