A neonate is found to have a congenital diaphragmatic hernia (CDH) with abdominal viscera herniating into the left pleural cavity. Through which embryological defect does this most commonly occur?

• A Failure of fusion of the septum transversum with the pleuroperitoneal membranes
• B Defect in the left pleuroperitoneal fold (foramen of Bochdalek) ✓
• C Defect in the right pleuroperitoneal fold (foramen of Morgagni)
• D Central tendon agenesis

Explanation

The most common congenital diaphragmatic hernia (~85% of cases) is a posterolateral defect through the left pleuroperitoneal fold, known as the foramen of Bochdalek. It results from failure of the pleuroperitoneal canal to close by the 8th week of embryological development. The left side predominates because the right side closes earlier (the liver also helps seal the right side). This allows small intestine, stomach, and even spleen to herniate into the left pleural cavity, compressing the developing lung.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.