Fetal Myelomeningocele Repair With Maternal BMI Between 35.0 and 40.0

Inclusion Criteria: * Maternal BMI 35.0 to 40.0 * No maternal documented co-morbidities * Fetal MMC begins between thoracic 1 and sacral 1, on the spinal column. * Evidence of fetal hindbrain herniation (hindbrain is being pulled down the spinal column). * A gestational age is between 19 weeks 0 days and 26 weeks with evidence of placental membrane fusion. * Documented normal fetal karyotype. Exclusion Criteria: * History of maternal alloimmunization problem * Kell sensitization * Risk of preterm birth * History of spontaneous preterm birth * Cervix \<20mm in length * Presence of cerclage * Placental problem * History of placental abruption * Placental Previa * Body-mass index of 40.1 or more * Maternal contraindication to surgery * Insulin-dependent pregestational diabetes * Hypertension or preeclampsia * HIV, hepatitis-B, or hepatitis-C positive * Other medical condition of risk to mother * Uterine problem * Previous hysterotomy in the active uterine segment * Severe fibroids * Uterine malformation (bicornuate, arcuate, unicornuate, didelphys) * No support person for periprocedural period * Inadequate support at home for pregnancy * Inadequate understanding of risks and benefits of fetal surgery * Inability to comply with medical restrictions, follow up after fetal surgery * Multiple gestation pregnancy (twins, triplets, etc.) * A fetal anomaly unrelated to myelomeningocele (heart defect, lung lesions) * Severe fetal kyphosis \>30 degrees (curvature of the back)