Congenital diaphragmatic hernia (CDH) is a defect in the formation of the diaphragm that is associated with pulmonary hypoplasia. CDH is thought to be due to failure of the pleuroperitoneal canal to close by 9 to 10 weeks of gestation.
- Approximately 60% of cases are isolated and 40% are complex or syndromic.
- Multiple sonographic and MRI techniques have been described to predict lung volume, which is an important predictor of survival. Liver position is also very important with regard to outcome.
- In the most severe cases of congenital diaphragmatic hernia (CDH), therapeutic innovations such as fetal tracheal occlusion with a balloon which is removed prior to delivery or EXIT to ECMO may offer the best hope for survival.
- All fetuses with CDH should be delivered in a tertiary center with specific neonatal and surgical expertise in this condition and ECMO capability.
- Cesarean section delivery is indicated only for standard obstetrical reasons or for ECMO standby.
- Approximately a dozen single-gene disorders have CDH as a major feature. With increased cytogenetic resolution through array cGH, more syndromic cases are being recognized as being associated with chromosome abnormality. Fetal karyotype is indicated in all cases.
- Incidence is around 1 in 2200 with 85% to 90% being left sided, 10% to 15% right sides and 2% bilateral.