Edema Abnormality of prenatal development or birth Hydrops fetalis SNOMEDCT_US:276508000 human_phenotype UMLS:C0020305 MSH:D015160 The abnormal accumulation of fluid in two or more fetal compartments, including ascites, pleural effusion, pericardial effusion, and skin edema. HP:0001789 The most common causes of hydrops fetalis are hematologic (inclusing isoimmunization because of Rhesus incompatibility and other causes), hereditary hemolytic disorders, fetal hemorrhage, disorders of red cell production), cardiovascular disorders, infections, certain intrathoracic malformations, and idiopathic forms.