Fetal Spina Bifida

The Stanford Children’s Health Fetal and Pregnancy Health program’s specialists in maternal-fetal medicine, pediatric radiology, neonatology, pediatric neurosurgery and pediatric surgery provide multidisciplinary evaluation, consultation and therapy for fetal spina bifida. We are the only program in California to offer multidisciplinary in utero fetoscopic neural tube defect repair under an IRB protocol with FDA oversight. We also provide the more common fetal repair for NTD via open fetal surgery. Our dedicated multidisciplinary spina bifida clinic at Stanford Children’s Health is prepared to care for your baby with spina bifida after delivery.

What is spina bifida?

Spina bifida is a condition in which there is abnormal development of the fetus’s bony spine, which leads the spinal cord and nerves to herniate into the amniotic cavity. The nerves may be covered by a sac (myelomeningocele), but the fetal cerebrospinal fluid (CSF) can leak into the amniotic fluid. The defect can occur anywhere along the spine, but it usually occurs along the lower segments of the spine (the lumbar and sacral regions).

Spina Bifida illustration

Treatment for fetal spina bifida

Benefits of fetal spina bifida in utero repair:

  • Decreased need for postnatal ventriculo-peritoneal shunt
  • Improved lower motor function (i.e., increased likelihood of walking without assistance)

Potential benefits of fetoscopic in utero fetal spina bifida surgery versus open fetal surgery:

  • Exposure of the fetal spine is performed via two to three small uterine ports rather than a hysterotomy (which is required for open fetal surgery)
  • Potential for vaginal trial of labor
  • Potential for delivery at later gestational ages compared with open fetal surgery.

Criteria for fetoscopic in utero repair (MOMS study criteria):

  • Isolated spinal lesion starting at or above S1
  • Chiari II malformation (brainstem herniation downward, small posterior fossa)
  • Surgery must be performed before 25 6/7 weeks
  • Normal karyotype or microarray testing via amniocentesis
  • Maternal BMI <35
  • No contraindications to in utero surgery – no prior myomectomy or any surgery on the uterus (other than cesarean)
  • Low risk for preterm birth – no history of preterm birth, normal cervical length
  • Evaluation includes ultrasound, MRI, fetal echocardiogram, amniocentesis and multidisciplinary consultation

What are the most common types of spina bifida?

  • Spina bifida occulta. A mild form of spina bifida in which the skin covers the spinal defect and the spinal cord and the nerves do not herniate into the amniotic cavity. This form of spina bifida may be characterized only by a hairy patch, dimple or birthmark over the area of the defect after delivery. Some babies with this condition require surgery at three to six months of age to de-tether the spinal cord.
  • Lipomyelomeningocele. A moderate form of spina bifida in which the skin is covers the spinal defect but there is fatty lump under the skin that is tethered to the spinal cord. Infants with this condition require surgery at three to six months of age to repair the defect.
  • Meningocele. A moderate form of spina bifida in which only a fluid-filled sac herniates outside the spine and the spinal nerves do not. This condition may require early repair after birth or in the first six months of the patient’s life, depending on the skin overlying the meningocele.
  • Myelomeningocele. A severe form of spina bifida in which the nerves herniate through the bony defect outside of the body and are covered by a thin fluid-filled sac. The nerves that are exposed to the amniotic cavity are damaged over time, leading to difficulty walking and problems with bladder and bowel function. These defects are repaired in utero or in the first one to two days of the patient’s life. A majority of babies with myelomeningocele will also have herniation of the brain into the base of the skull (Chiari II malformation), which leads to a buildup of extra fluid in the brain (hydrocephalus). Babies with hydrocephalus need a shunt or an endoscopic procedure after delivery in order to reduce the pressure in the brain.