Safety and Efficacy of Fetoscopic Endoluminal Tracheal Occlusion (FETO) in Congenital Diaphragmatic Hernia (CDH)

FETO Intervention Arm: Inclusion Criteria: * Provision of signed and dated informed consent form * Stated willingness to comply with all study procedures and availability (meets psychosocial criteria below) for the duration of the study * Pregnant women, age 18 years and older * Singleton pregnancy * Normal fetal karyotype, Chromosomal Microarray (CMA) with non-pathologic variants, Whole Exome Sequencing (WES) or Whole Genome Sequencing (WGS). Results by fluorescence in situ hybridization (FISH) will be acceptable if the patient is \>26 weeks. * Gestational age at enrollment prior to 29w6d * Fetal CDH with intrathoracic liver herniation with either: * Isolated left CDH with Observed/Expected (o/e) Lung to Head Ratio (LHR) \<30% at enrollment (18w0d-29w5d) * Isolated right CDH with o/e LHR \<45% at enrollment (18w0d-29w5d) * Cervical length by transvaginal ultrasound \>20 mm within 24hours of FETO procedure * Meets psychosocial criteria * Willing to reside within 30 minutes of Von Voigtlander Women's Hospital and ability to maintain follow up appointments * Patient has a support person (e.g. spouse, partner, friend, parent) that is available to stay with participant for the duration of the pregnancy near Von Voigtlander Women's Hospital * Willing to comply with restrictions of daily living including inability to exercise, have intercourse, or return to work (work from home approved by Principal Investigator is okay) Expectant Management Arm: Inclusion Criteria: …