Open fetal myelomeningocele repair for spina bifida

What is open fetal myelomeningocele (MMC) repair?

This complex and highly orchestrated procedure treats the most severe form of spina bifida, myelomeningocele, before the baby is born. It repairs the incomplete spinal canal so that the spinal cord and tissues (meninges) no longer protrude from the baby’s back. The surgical repair is similar to the standard procedure usually done after birth, but fixing the defect while the baby is still in the womb helps protect his or her spine from further damage and stops the leakage of cerebrospinal fluid.

During the procedure, the mother and baby are asleep under general anesthesia and given medications for pain control. The operating room team includes multidisciplinary experts dedicated to caring for mom and baby: maternal fetal medicine specialists, fetal surgeons, the neurosurgeon who makes the repair, a pediatric cardiologist who monitors the baby’s heartbeats, and anesthesiologists for both the baby and mother.

After making the incision in the mother, the fetal surgeon opens the uterus away from placenta to expose the baby’s back. Keeping the baby in the womb, the medical team infuses warm fluids into the uterus to keep amniotic fluids normal, allowing the fetus and umbilical cord to continue to float and remain safe. The neurosurgeon uses the surrounding muscle and skin to close the opening in the baby’s back and protect the spinal cord. After the neural defect is repaired, the fetal surgeon then closes the mom’s uterus and abdominal incision. Mother and baby are also given antibiotics to prevent infection. The entire procedure takes approximately two hours.

Candidates for in-utero surgery

Not every baby with spinal bifida is a candidate for this surgery. For safety’s sake, patients must meet the following criteria:

• The myelomeningocele must be located within a specific area of the back.
• The surgery must be done within a certain time period in the pregnancy — between 19-25 weeks.
• The baby must not have a genetic problem or any other major birth defect.
• The baby must have a normal echocardiogram (an ultrasound picture of the heart).
• The mother must be pregnant with only one baby.
• The mother cannot be obese (with a body mass index higher than 35).
• The mother must not have any one of a number of health conditions.

While prenatal surgery offers potential benefits, it also carries risks for both the mother and the baby, including an increased likelihood of premature labor. The specialists at the Fetal Concerns Center will help you decide whether prenatal surgery is the right option for you and your baby.

How does in-utero MMC repair affect my baby?

Babies who undergo surgical repair prenatally tend to do better: Research shows they are less likely to need a ventriculoperitoneal shunt (a tube that helps drain excessive fluid from brain) and are more likely to have better muscle and walking skills than those who have the traditional surgery after birth. However, the surgery is not a cure for spina bifida, and your child may still have problems with walking and urine/bowel function. At the Fetal Concerns Center, only 22% of fetal myelomeningocele surgery patients have required ventricular shunting post-surgery.*

*Based on data from 2012 - 2016.

How does in-utero MMC repair affect the pregnancy?

To decrease the risk of preterm delivery, you will need to remain on modified bed rest after the surgery. You will be closely monitored by our Fetal Concerns Center for the rest of your pregnancy, and you will need to deliver your baby via a scheduled Cesarean section at 37 weeks, unless you go into labor earlier. Most Milwaukee-area patients receive care at our Fetal Concerns Center and then deliver at the Froedtert & the Medical College of Wisconsin Birth Center, though in some cases it’s possible for mothers to receive follow-up care and deliver at another hospital closer to home.

What happens after my baby is born?

If you deliver at Froedtert, your baby will receive top-notch care in Children’s Wisconsin’s Level IV Neonatal Intensive Care Unit, which is ranked as one of the best in the nation. We will closely monitor your baby, using ultrasounds to check his or her head, kidneys and bladder, and MRI to check the spine and brain. Your child might require a catheter to help with urine elimination or a shunt to drain excess fluid from the brain.

Will I be able to help care for my baby?

Absolutely. Our recently expanded and redesigned NICU was created to promote family bonding, with private rooms where parents can stay with their baby 24/7, and other special features for families’ comfort. Our on-call lactation specialists can help you successfully breastfeed and pump and store breast milk when direct breastfeeding isn’t an option.

When can my baby go home?

The incision in your baby’s back needs to heal before he or she can go home. Some babies may need only a brief stay in the NICU, while others may need more time in the hospital to resolve health issues. Premature babies will likely need a longer NICU stay. After discharge, your child will require ongoing monitoring by Children’s Wisconsin's multidisciplinary Spina Bifida Program or another clinic close to your home.

What’s my baby’s long-term prognosis?

In-utero repair is still a relatively new procedure, and researchers continue to collect data on how long-term outcomes compare with babies who have the standard procedure after birth. In general, outcomes for children with spina bifida vary depending on the severity of the defect and other factors. Some children experience only minimal side effects, especially if the defect is very low on the spine. Nerve damage higher in the spine affects more of the body’s function and is more likely to cause problems with mobility. Even after surgical repair of the spinal cord, your child may still experience nerve issues. Your child may also have a higher risk of learning problems and seizures and could develop other problems with the spinal cord as he or she grows.

What about future pregnancies?

Your chances of having another baby with spina bifida are higher than the general public: 1 in 25, or 4 percent. Your doctor will likely prescribe high doses of folic acid (preferably before you conceive) to reduce the odds of your baby developing spina bifida. Because the surgical scar on your uterus puts you at increased risk of uterine rupture during childbirth, you will need to wait two years between pregnancies and deliver all future babies via planned Cesarean section no later than 37 weeks.