Congenital lung and airway malformations — structured oral (viva)

Branch 1 — Antenatal risk stratification

Examiner: "You are the fetal-medicine registrar. How do you decide how worried to be about this lesion?" Candidate: The raw size matters less than its physiological effect, so I focus on the mediastinal shift, the compression of the heart and great veins, and any early signs of hydrops such as skin oedema, ascites or a pericardial effusion. I would quantify the lesion using the CPAM volume ratio, a size index that predicts the risk of hydrops and directs how intensively the pregnancy is monitored, and I would follow it with serial ultrasound. A large solid microcystic lesion with a rising volume ratio and early hydrops marks this fetus as high risk. ^{[1] [2]}