Female Reproductive System
Male Reproductive System
Before birth, there is a canal between the belly button and the bladder called the urachus. In most cases this canal goes away before birth. But sometimes part of the urachus remains after birth. The urachus has no purpose after birth, so if it remains it can cause health problems. These problems are called “urachal abnormalities.”
Problems with a urachal abnormality are rare. They can be seen in infants or children, and rarely in adults. It is unclear why this happens.
What Happens Under Normal Conditions?
As a baby develops, the bladder is formed in the lower belly of the growing fetus. This organ is joined with the umbilical cord by a thick cord called the urachus. After the first few weeks of growth, this thick path to and from the placenta has blood vessels, a channel (that will later become the intestine), and a tube called the allantois.
The inside of the allantois is joined to the top of the growing bladder. This link from the top of the bladder to the belly button is formed in about 20 weeks.