Lung‐to‐head ratio : a need to unify the technique

Abstract

Congenital diaphragmatic hernia (CDH) is associated with a high postnatal mortality rate due to pulmonary hypoplasia and/or hypertension. Antenatal prediction of postnatal outcome is based essentially on the assessment of the degree of intrathoracic compression of the lungs, and the most widely used method is ultrasonographic measurement of the fetal lung area‐to‐head circumference ratio (LHR). In the assessment of fetuses with CDH and the counseling of parents as to the available options (including endoscopic occlusion of the fetal trachea1-3, expectant management and pregnancy termination) for subsequent management of the pregnancy, it is imperative that prediction of outcome is as accurate as possible. Consequently, operators undertaking measurement of LHR should be trained appropriately4 and correct algorithms used for interpretation of the results