Patent urachus is a type of congenital urachal anomaly (see this term) characterized by a persistent communication between the bladder and the umbilicus, secondary to non occlusion of the urachal lumen, manifesting as clear drainage from the umbilicus.

Single umbilical artery (SUA) is the absence of one of the two umbilical arteries surrounding the fetal bladder and in the fetal umbilical cord.