Fetoscopic Endoluminal Tracheal Occlusion (FETO) for Congenital Diaphragm Hernia

Inclusion Criteria:

• Pregnant women age 18 years and older

• Singleton pregnancy

• Normal fetal karyotype with confirmation by culture results. Results by fluorescencein situ hybridization (FISH) will be acceptable if the patient is > 26 weeks

• Isolated Left CDH with liver up

• O/E LHR < 30% - Gestation age at time of enrollment prior to 29 wks plus 5 days asdetermined by clinical information (LMP, 1st or 2nd trimester ultrasound) andevaluation of first ultrasound (measured at 270 to 296 weeks) at the time of surgery

• Gestational age at FETO procedure with O/E LHR < 30% at 27 weeks 0 days to 29 weeks 6 days as determined by clinical information (LMP) and evaluation of firstultrasound

• Patient meets psychosocial criteria

• Informed consent

Exclusion Criteria:

• Patient < 18 years of age

• Multi-fetal pregnancy

• History of natural rubber latex allergy

• Preterm labor, cervix shortened (<15 mm at enrollment or within 24 hours of FETOballoon insertion procedure) or uterine anomaly strongly predisposing to pretermlabor, placenta previa

• Psychosocial ineligibility, precluding consent: Inability to reside within 30minutes of The Fetal Center at Children's Memorial Hermann Hospital. and inabilityto comply with the travel for the follow-up requirements of the trial; Patient doesnot have a support person (e.g. spouse, partner, mother) available to stay with thepatient for the duration of the pregnancy at The Fetal Center at Children's MemorialHermann Hospital.

• Right sided CDH or bilateral CDH, isolated left sided with O/E LHR ≥25% (measured at 18 weeks 0 days to 29 weeks 5 days) as determined by ultrasound[1]

• Additional fetal anomaly and chromosomal abnormalities by ultrasound, MRI, orechocardiogram at the fetal treatment center. No cases will be removed post hoc ifabnormalities are discovered in the course of post-operative monitoring

• Maternal contraindication to fetoscopic surgery or severe maternal medical conditionin pregnancy

• History of incompetent cervix with or without cerclage

• Placental abnormalities (previa, abruption, accrete) known at time of enrollment

• Maternal-fetal Rh isoimmunization, Kell sensitization or neonatal alloimmunethrombocytopenia affecting the current pregnancy

• Maternal HIV, Hepatitis-B, Hepatitis-C status positive because of the increased riskof transmission to the fetus during maternal-fetal surgery. If the patient's HIV orHepatitis status is unknown, the patient must be tested and found to have negativeresults before enrollment

• Uterine anomaly such as large or multiple fibroids or mullerian duct abnormality

• There is no safe or technically feasible fetoscopic approach to balloon placement

• Participation in another intervention study that influences maternal and fetalmorbidity and mortality or participation in this trial in a previous pregnancy