North American Fetal Therapy Network for Long-term Outcome Following Fetoscopic Endoluminal Tracheal Occlusion in Severe Left and Right Congenital Diaphragmatic Hernia

Participants will undergo FETO surgery at at 27 weeks 0 days - 29 weeks 6 days gestation.Balloon insertion into the fetal trachea will be performed. This will be followed by weekly \\ ultrasound monitoring and MRI at 3 weeks following FETO insertion and removal of the balloon which will be performed at at 34 weeks 0 days to 34 weeks 6 days. Planned delivery will occur after 37 weeks. The follow-up phase will be conducted from birth to 24 months of age