Patient Basics: Spina Bifida

Spina bifida is a birth defect in which the spine and spinal cord don’t close completely while a baby is growing in the womb. It can be so mild that it’s never noticed, or it can cause weakness in the legs and problems with bladder and bowel control. Taking folic acid every day before and early in pregnancy greatly lowers the chance of it happening. With surgery and ongoing care, most children with spina bifida grow up to be active adults.

Key points

• Spina bifida forms in the first month of pregnancy, often before a person knows they are pregnant.
• The most serious type, myelomeningocele, leaves part of the spinal cord exposed in a sac on the baby’s back.
• It’s usually found on a prenatal blood test or ultrasound.
• Surgery closes the opening, either soon after birth or, at some centers, before birth.
• Many children also need treatment for fluid on the brain (hydrocephalus), and help with walking, bladder and bowel care.

Types of spina bifida

Early in pregnancy, a flat strip of cells rolls up into a tube that becomes the brain and spinal cord (the neural tube). It should close by about 4 weeks after conception. Spina bifida happens when part of the lower end doesn’t close, leaving a gap in the bones of the spine.

• Spina bifida occulta (“hidden”) is the mildest and most common type. There’s a small gap in one or more back bones, but the spinal cord and nerves are usually fine. Most people never have symptoms. A dimple, a tuft of hair, a fatty lump or a birthmark over the lower back can be a clue.
• Meningocele is a sac of fluid that pushes out through the gap. The spinal cord isn’t in the sac, so there may be little or no nerve damage.
• Myelomeningocele is the most serious type. Part of the spinal cord and nerves sit in a sac on the back, or are open to the air. This damages the nerves below that point. The higher on the back it is, the more the body is affected.

What causes spina bifida

Usually there’s no single cause. It seems to come from a mix of genes and things in the environment. Known risk factors include:

• Not getting enough folic acid (folate, a B vitamin) before and in early pregnancy
• A previous pregnancy affected by a neural tube defect, or a parent with one
• Some seizure medicines, especially valproate
• Diabetes that isn’t well controlled, and obesity
• High body heat early in pregnancy, such as a long fever or hot tub use

Nothing a parent did in later pregnancy causes it.

How spina bifida is found

Before birth

• Blood test. At about 15 to 20 weeks, a test of the mother’s blood measures alpha-fetoprotein (AFP), a protein made by the baby. A high level can be a sign of an open neural tube defect.
• Ultrasound. The detailed scan at about 18 to 22 weeks finds most cases. It can show the opening in the spine and changes in the baby’s head.
• Fetal MRI or amniocentesis may give more detail. Amniocentesis tests a small sample of the fluid around the baby.

After birth

Meningocele and myelomeningocele can be seen at birth. Spina bifida occulta is often found by chance on an X-ray. If a baby has skin signs over the lower back, an ultrasound or MRI can check for a tethered spinal cord, where the cord is stuck to nearby tissue.

Spina bifida treatment

Closing the opening

A baby with myelomeningocele usually has surgery within a day or two of birth. The surgeon places the spinal cord back inside the spine and closes the skin to prevent infection. At some specialized centers, surgeons can repair it during pregnancy, before 26 weeks. Surgery before birth lowers the chance that the baby will need a brain shunt and can improve walking, but it raises the risk of early birth. Surgery can’t undo nerve damage that has already happened.

Hydrocephalus

Most babies with myelomeningocele build up extra fluid in the brain. A thin tube called a shunt can drain it into the belly. Some children can have a small opening made inside the brain instead (endoscopic third ventriculostomy). Many also have a Chiari II malformation, where the lower part of the brain sits lower than normal. It usually causes no trouble, but it can affect swallowing or breathing in some babies.

Lifelong care

Children do best with a spina bifida clinic team. It often includes a neurosurgeon, urologist, orthopedic surgeon, physical therapist and others.

Living with spina bifida

• Moving around. Depending on how the nerves are affected, a child may walk without help, use leg braces or crutches, or use a wheelchair. Physical therapy builds strength and keeps joints flexible.
• Bladder. Many people empty the bladder several times a day with a thin tube (catheter), which children can learn to do themselves. Medicines and regular kidney checks help protect the kidneys.
• Bowel. A daily bowel routine, diet changes and sometimes enemas help prevent accidents and constipation.
• Skin. Skin with little feeling can get pressure sores or burns without the person noticing. Check the skin every day.
• Latex allergy. This is common in people with spina bifida. Use latex-free gloves, catheters and balloons.
• Learning. Some children have trouble with attention, organizing tasks or math. School support plans can help.
• Growing up. As a child grows, a tethered cord can cause new back pain, weaker legs or bladder changes. Adults need a plan for moving from child to adult care.

Lowering the risk

• Anyone who could become pregnant should take a daily vitamin with folic acid, starting at least a month before pregnancy.
• If you’ve had a pregnancy with a neural tube defect, ask about a higher, prescription amount.
• If you take a seizure medicine, talk to your doctor before trying to get pregnant. Don’t stop it on your own.
• Get diabetes under good control before pregnancy, and treat fevers early in pregnancy.

When to get care

For a child with a shunt, get emergency care for headache, vomiting, unusual sleepiness, crankiness, a seizure, a bulging soft spot in a baby, or swelling or redness along the shunt. These can mean the shunt is blocked or infected.

See the care team soon for new back pain, weaker legs, changes in bladder or bowel habits, fever with cloudy urine, or a skin sore that won’t heal.

Common questions about spina bifida

Is spina bifida occulta serious?

Usually not. Most people with spina bifida occulta have no symptoms and find out by chance. A small number have a tethered spinal cord, which can cause back pain, leg weakness or bladder problems. If a baby has a dimple, hair tuft or lump over the lower back, a doctor may order a scan.

Can people with spina bifida walk?

Many can. It depends mostly on where the opening is along the spine. People with a lower opening often walk with or without braces. Those with a higher opening are more likely to use a wheelchair, at least part of the time. Physical therapy helps each child move as well as they can.

What is the life expectancy with spina bifida?

Most children with spina bifida now live into adulthood, and many have long lives. Kidney problems and shunt failures used to cause many early deaths. Better bladder care and shunt care have changed that. Regular checkups throughout life help find problems early.

Is spina bifida genetic?

Genes play a part, but most babies with spina bifida have no family history of it. Having one affected pregnancy raises the chance in the next one. A genetic counselor can explain your risk and how to lower it, including taking a higher amount of folic acid.

Questions to ask your doctor

• Which type of spina bifida does my child have, and at what level?
• Is surgery before birth an option for us?
• What signs of shunt trouble should I watch for?
• What bladder and bowel care will my child need?
• How can we lower the risk in a future pregnancy?

Learn more

• About spina bifida (Centers for Disease Control and Prevention)
• Spina bifida (National Institute of Neurological Disorders and Stroke)

This guide is general information and doesn’t replace advice from your own doctor. Last updated October 2026.