Feto-Endoscopic Tracheal Occlusion (FETO) for Severe Congenital Diaphragmatic Hernia

Inclusion Criteria:

* Isolated CDH with liver up
* Severe pulmonary hypoplasia with ultrasound O/E LHR \<25% at the time of surgery
* Gestational age at FETO procedure 27 weeks 0 days to 29 weeks 6 days
* Moderate pulmonary hypoplasia with ultrasound O/E LHR \<30% and liver-up at the time of surgery
* Gestational age at FETO procedure 30 weeks 0 days to 31 weeks 6 days in this moderate category
* Maternal age greater than or equal to 18 years
* Gestational age at enrollment prior to 29 weeks 6 days, or 31 weeks 6 days in moderate category
* Normal karyotype or FISH
* Normal fetal echocardiogram
* Singleton pregnancy
* Willing to remain in the greater Cincinnati area for remainder of pregnancy
* Family considered and decline option of termination of the pregnancy at less than 24 weeks 0 days
* Family meets psychosocial criteria

Exclusion Criteria:

* Patient \< 18 years old
* Multi-fetal pregnancy
* Rubber latex allergy
* Preterm labor, cervix shortened (\<15 mm) or uterine anomaly strongly predisposing to preterm labor, placenta previa
* Bilateral CDH, isolated left sided CDH with an O/E \> 30%
* Additional fetal anomaly by ultrasound, MRI, or echocardiogram
* Chromosomal abnormalities
* Maternal contraindications to fetoscopic surgery or severe maternal condition in pregnancy
* Incompetent cervix with or without a cerclage
* Placental abnormalities known at time of enrollment
* Maternal HIV, Hepatits B, Hepatitis C
* Maternal uterine anomaly
* No safe or technically feasible fetoscopic approach to balloon placement
* Participation in another intervention study that influences maternal and fetal morbidity and mortality or participation in this trial in a previous pregnancy