A Study to Evaluate Minimally Invasive Fetoscopic Regenerative Repair of Spina Bifida


About this study

The purpose of this study is to evaluate a new, minimally-invasive technique (fetoscopic repair) for repair of spina bifida (MMC) during the second trimester of pregnancy. Researchers are trying to determine if this less invasive surgical approach will have less risk to the mother and, at the same time, adequate closure of the fetal spina bifida defect.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Pregnant women - maternal age 18 years or older.
  • Gestational age at the time of the procedure between 19 0/7 weeks and 25 6/7 weeks.
  • Singleton pregnancy.
  • Myelomeningocele (Spina Bifida, "MMC"), diagnosis with the upper boundary located between Thoracic 1 (T1) and Sacral 1 (S1).
  • Evidence of hindbrain herniation (confirmed on MRI to have an Arnold-Chiari type II malformation).
  • Absence of chromosomal abnormalities and associated anomalies.
  • Normal karyotype and/or normal chromosomal microarray (CMA) by invasive testing (amniocentesis or CVS). If there is a balanced translocation with normal CMA with no other anomalies the candidate can be included.
  • Family has considered and declined the option of termination of the pregnancy at less than 24 weeks.
  • Family meets psychosocial criteria (sufficient social support, ability to understand requirements for this study).
  • Pregnant subject capable of consenting for their own participation in this study.
  • Willingness to undergo an open MMC repair, if necessary.
  • Parental/guardian permission (informed consent) for follow up of child after birth.

Exclusion Criteria:

  • Fetal anomaly unrelated to MMC.
  • Multiple gestation.
  • Declined invasive testing for karyotype (amniocentesis or CVS).
  • Severe kyphosis (defined as curvature of the spina (vertebras) higher than 30° measured by ultrasonography or magnetic resonance imaging).
  • Increased risk for preterm labor including short cervical length (< 2.0 cm), history of incompetent cervix with or without cerclage, and previous preterm birth.
  • Placental abnormalities (previa, abruption, accreta) known at time of enrollment.
  • A body-mass index ≥ 40 at first prenatal visit.
  • Contraindications to surgery including previous hysterotomy (whether from a previous classical cesarean, uterine anomaly such as an arcuate or bicornuate uterus, major myomectomy resection, or previous fetal surgery) in active uterine segment.
  • Technical limitations precluding fetoscopic surgery, such as uterine fibroids, fetal membrane separation, uterine anomalies incompatible with fetoscopy.
  • Amniotic Fluid Index (AFI) < 6 cm if deemed to be due to fetal anomaly, poor placental perfusion or function, or membrane rupture. Low amniotic fluid volume that responds to maternal hydration is not an exclusion.
  • Maternal-fetal Rh isoimmunization, Kell sensitization or neonatal alloimmune thrombocytopenia affecting the current pregnancy.
  • Maternal HIV, Hepatitis-B, Hepatitis-C status positive because of the increased risk of transmission to the fetus during maternal-fetal surgery. If the patients HIV or Hepatitis status is unknown, the patient must be tested and found to have negative results before enrollment.
  • Maternal medical condition that is a contraindication to surgery or anesthesia.
  • Patient does not meet other psychosocial criteria, as determined by the psychosocial interviewer using a standardized assessment, to handle the implications of the trial.
  • Maternal hypersensitivity to collagen.
  • Patient does not have a support person (i.e., spouse, partner, mother) available to support the patient for the duration of the pregnancy.
  • Inability to comply with the travel and follow-up requirements of the trial.
  • Participation in another intervention study that influences maternal and fetal morbidity and mortality or participation in this trial in a previous pregnancy.


Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Edward Ahn, M.D.

Closed for enrollment

Contact information:

Shonie Buenvenida R.N.



More information


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