ABSTRACT
Congenital diaphragmatic hernia (CDH) is a common malformation characterized by a defect in the posterolateral diaphragm, the foramen of Bochdalek, through which the abdominal viscera migrate into the chest during fetal life. Population-based studies have reported the prevalence of CDH to be between 1 in 2500 and 1 in 3000 live births.1 , 2 A recent study reported the prevalence of CDH in Europe to be 2.3 per 10,000 births for all cases and 1.6 per 10,000 births for isolated cases.3 Approximately 80% of the CDH cases are left sided, 15% are right sided, and less than 5% are bilateral.4 , 5 The size of the defect varies from small (2 or 3 cm) to vary large, involving most of the hemidiaphragm. The international committee of the Congenital Diaphragmatic Hernia Study Group (CDH Study Group), recently created a standardized four-grade (A to D) reporting system for CDH6: A defects are completely surrounded by muscle. B defects have a small and C defects a large portion of the chest wall devoid of diaphragm tissue. D defects present with a complete or near-complete absence of the diaphragm. The size of the diaphragmatic defect and also a potential severe cardiac anomaly were shown to worsen the outcome.6 Despite advances in neonatal resuscitation and intensive care, newborn infants with CDH continue to have high mortality. Current survival rates in population-based studies are around 55%–80%.4 , 5 , 7 Highly specialized centers report up to 90% survival but discount the hidden mortality, mainly in the antenatal period.8 The high mortality and morbidity in CDH are mainly attributed to pulmonary hypoplasia and persistent pulmonary hypertension.8 – 10
