RecruitingDevice studyProspective Registry for Long-term Outcomes Following FETO in Severe Left and Right CDHThis registry study aims to confirm that FETO increases neonatal survival to discharge and reduces long-term morbidity in fetuses with isolated left CDH and o/e LHR \< 30%, or isolated right CDH and o/e LHR ≤ 45%, compared to those receiving standard care. This prospective registry plans to enroll 80 pregnant women (40 treatment/40 control) with fetuses diagnosed with isolated CDH, and the children will be followed for up to 24 months.