'TOTAL' (Tracheal Occlusion To Accelerate Lung Growth) Trial

This is a multi-center, non-blinded randomized controlled trial in fetuses with isolated moderate CDH, i.e. moderate lung hypoplasia (as determined by prenatal assessment of lung development). It essentially compares fetal therapy added to conventional postnatal care, versus expectant prenatal management during pregnancy followed by conventional postnatal care. Enrollment: Following completion of an inclusion/exclusion criteria checklist and obtaining informed consent, the subject will be randomized into two groups ("FETO" and "expectant"). Procedures: Group I: Standardized postnatal care (expectant group): mothers will be expectantly managed during pregnancies and babies receive standardized postnatal care at a tertiary center used to manage babies with CDH. The recommendation is that they adhere to consensus guidelines published on the study website. Group II: Prenatal intervention (FETO group): patients will undergo fetoscopic tracheal occlusion and ideally prenatal reversal of the occlusion followed by standardized postnatal care as in I. In this study FETO is to be done between 30 weeks plus 0 day and 31 weeks plus 6 days and removal of the balloon at 34 weeks plus 0 day to 34 weeks plus 6 days. This study trial is a pragmatical or efficacy trial: ideally mothers will deliver after removal of the balloon at those tertiary centers, typically offering postnatal care for the patient involved. In group II (FETO-group), mothers will, in between placement and removal of the balloon, thus carrying a fetus with obstructed airways, ideally remain under the care of our local fetal treatment center (further referred to as FETO center). As many as possible precautions are taken to avoid problems with balloon removal in case of earlier than expected delivery. * Balloons are to be electively removed prior to 35 weeks. FETO centers will provide 24/24 hours and 7/7 days services for management of fetuses with obstructed airways, either in utero or during labor and delivery. * Patients in the study and randomized to FETO, will be encouraged to stay near the FETO center. After reversal of the occlusion the patient will be referred to the tertiary care center where delivery and postnatal care will be undertaken. If the patient is not remaining at or close to the FETO center, the postnatal treatment center should organize likewise EXIT services.