Fetal Intra‐pericardial Morgagni Hernia with effusion affecting one member of a twin gestation

Congenital diaphragmatic hernia (CDH) is a rare type of developmental defect of the diaphragm, occurring in 1 per 2000 pregnancies. Morgagni hernia, in particular, which results from an anterior defect of the diaphragm, is the least common type of CDH (5%). Herniation of the liver into the pericardial space, presenting as a thoracic mass with pericardial effusion, is an extremely rare form of Morgagni hernia. Such reported cases are few and occurred only in singleton pregnancies. To the best of our knowledge, we report the first case of fetal echocardiography and fetal MRI following referral due to large pericardial effusion.