Congenital diaphragmatic hernia: Pathophysiology

Introduction: Congenital diaphragmatic hernia (CDH) occurs in 1 in 2000 to 1 in 3800 births [1, 2]. Prenatal diagnosis carries a 2–4 times greater mortality perhaps related to larger defects and more severe pulmonary hypoplasia or associated anomalies in these infants. For fetuses identified prenatally, 25–70% are born alive of which approximately 55% survive to discharge [1–3]. Seventy percent of postnatal deaths occur within the first 24 hours [4]. Major non-pulmonary malformations occur in 15–72% of prenatally detected cases. This is associated with a fourfold increase in mortality rate compared to infants with isolated CDH; 95% of stillbirths and 60% of infants dying within the first 24 hours have non-pulmonary major malformations [3]. The diaphragmatic defect: The most common diaphragmatic defect is the posterolateral defect (Bochdalek hernia). Anterior defects (Morgagni hernias) or total agenesis of the hemi-diaphragm are also seen. Diaphragmatic defects occur on the let in 80–90%, on the right in 5–15%, and bilateral or anterior Morgagni hernias in 2–5% of infants [3].