Ectopia cordis results from a failure of proper maturation of midline mesoderm and ventral body wall (chest) formation during embryonic development.The exact etiology remains unknown, but abnormalities in the lateral body wall folds are believed to be involved. Normally, the lateral body walls are responsible for fusion at the midline to form the ventral wall. Corruption of this process may underlie ectopia cordis. Defective ventral body wall formation yields a heart unprotected by the pericardium, sternum, or skin. Other organs may also have formed outside the skin, as well. Many cases of ectopia cordis have associated congenital heart defects, in which the heart has failed to properly form. Defects more commonly associated with ectopia cordis include: Intracardiac defects Atrial septal defect Ventricular septal defect Tetralogy of Fallot Tricuspid atresia Double outlet right ventricle Non-cardiac malformations Pentalogy of Cantrell Omphalocele Anterior diaphragmatic hernia Cleft palate Due to the rarity and rapid postpartum mortality of ectopia cordis, limited treatment options have been developed. Only some successful surgeries have been performed as of now, and the mortality rate remains high.