Fetoscopy/methods; Meningomyelocele/physiopathology; Meningomyelocele/surgery; Spina Bifida Cystica/surgery; Arnold-Chiari Malformation/diagnostic imaging; Arnold-Chiari Malformation/mortality; Arnold-Chiari Malformation/physiopathology; Arnold-Chiari Malformation/surgery; Comorbidity; Disability Evaluation; Female; Follow-Up Studies; Gestational Age; Humans; Infant; Infant, Newborn; Intraoperative Complications/diagnostic imaging; Intraoperative Complications/mortality; Intraoperative Complications/physiopathology; Intraoperative Complications/surgery; Male; Meningomyelocele/diagnostic imaging; Meningomyelocele/mortality; Muscle, Skeletal/diagnostic imaging; Muscle, Skeletal/physiopathology; Neurologic Examination; Postoperative Complications/diagnostic imaging; Postoperative Complications/mortality; Postoperative Complications/physiopathology; Prognosis; Risk Factors; Spina Bifida Cystica/diagnostic imaging; Spina Bifida Cystica/mortality; Spina Bifida Cystica/physiopathology; Treatment Outcome; Ultrasonography, Prenatal