Safety and Efficacy of FETO in CDH Phase III

Inclusion Criteria: * Pregnant women 18 years and older, who are able to consent * Singleton pregnancy * Gestational age at enrollment is prior to 296 weeks * Intrathoracic liver herniation * Isolated Left CDH with o/e LHR \< 30% at enrollment (180 to 295 weeks) or * Isolated Right CDH with o/e LHR \< 45% at enrollment (180 to 295 weeks) * Normal fetal karyotype with confirmation by culture results, CMA with non-pathological variants, WES or WGS. Results by fluorescence in situ hybridization (FISH) will be acceptable if the patient is \> 26 weeks * Cervical length by transvaginal ultrasound \> 20 mm within 24 hours prior to FETO procedure * Patient meets psychosocial criteria * Informed consent understood Exclusion Criteria * Patient \< 18 years of age * Multi-fetal pregnancy * History of natural rubber latex allergy * Preterm labor, cervix shortened (\< 20 mm at enrollment or within 24 hours prior to FETO balloon insertion) or uterine anomaly strongly predisposing to preterm labor, or placenta previa. * Psychosocial ineligibility, precluding consent: * Inability to reside within 30 minutes of Cincinnati Children's Hospital Medical Center and inability to comply with the travel for the follow-up requirements of the trial. * The patient does not have a support person (e.g. spouse, partner, mother) available to stay with the patient for the duration of the pregnancy at Cincinnati Children's Hospital Medical Center. * Bilateral CDH, isolated LCDH with o/e LHR ≥ 30%, isol…