Antenatal diagnosis of a Morgagni hernia in the second trimester.

Morgagni hernia is an uncommon type of congenital hernia that is rarely diagnosed antenatally. Herniation of the liver into the fluid-filled pericardial sac resulting in a thoracic mass is a particularly rare form of Morgagni hernia; only 3 cases have been reported in the literature, all with a diagnosis made at 32 weeks' gestation or later. We report a case of Morgagni hernia diagnosed on antenatal sonography at 24 weeks' gestation.