Umbilical hernia
A very common congenital malformation in which a hernia is present at the site of the umbilicus in the newborn; although sometimes quite large, these hernias tend to resolve without any treatment by the age of 5. Obstruction and strangulation of the hernia is rare because the underlying defect in the abdominal wall is larger than in an inguinal hernia of the the newborn.
Babies are prone to this malformation because of the process during fetal development by which the abdominal organs form outside the abdominal cavity, later returning into it through an opening which will become the umbilicus.
Importantly this type of hernia must be distinguished from a para-umbilical hernia which occurs in adults and involves a defect in the midline near to but not through the umbilicus.