In Utero Fetoscopic Repair Program for Sacral Myelomeningoceles and Mye-LDM

Inclusion Criteria: Inclusion Criteria : * Pregnant women age 18 years and older who are able to consent * Singleton pregnancy before 26 weeks of gestation, * Sacral MMC (upper level S1 or below) or MyeLDM diagnosed on ultrasound and MRI, 4. Absence of associated malformation apart from the anomalies usually observed in cases of open dysraphisms (i.e. feet malpositions, associated cerebral signs) or chromosomal anomaly if verification of the karyotype was desired by the couple * Affiliated to health insurance, understanding and speaking French * Written consent of the patient for the surgery and representatives of the parental authority for the postnatal follow-up of the child * Patient who made the choice to continue the pregnancy Exclusion Criteria: * Abnormal angulation of the fetal spine, * risk factors for prematurity: cervical length less \< 15mm, history of late miscarriage before 22 weeks, pre-existing rupture of the membranes at inclusion, * Placenta praevia, * BMI greater than 35 kg / m2, * Abnormality of the uterus: large fibroid, uterine malformation, history of uterine body surgery * Maternal infection at risk of maternal-fetal transmission: HIV, HBV, HCV, * Surgical or anesthetic contraindication. * Participation in another interventional research protocol, * Patients under legal protection (guardianship, curatorship). * Allergies to drugs used in the research