Prenatal Endoscopic Repair of Fetal Spina Bifida

Inclusion Criteria: * Patient \> 18 years old, with an assumption by health insurance, understanding and speaking French * A term \< or = 26 +0 weeks gestational age * Single-Pregnancy * Myelomeningocele with higher-level defect between S1 and T1 * Arnold Chiari anomaly * No associated anomaly or chromosic anomaly Exclusion Criteria: * severe foetal kyphoscoliosis associated * Increased risk of preterm birth: cervical length \<15 mm, history of at least 2 late miscarriages, existing premature rupture of membrane * placenta previa, accreta or placental abruption * Maternal obesity with BMI\> 35 * Uterine anomalies : large interstitial uterine fibroid, uterine malformation * maternal infection with a foetal transmission risk: HIV, HBV, HCV * Maternal contradiction in surgery or anesthesia * poor social status and/or social isolation * impossible post-surgery follow-up * want to have a medical pregnancy termination