What causes vesicoureteral reflux (VUR)?
A child can be born with vesicoureteral reflux, or VUR, or it can develop over time
There are two forms of vesicoureteral reflux (VUR), primary and secondary. Primary and secondary forms of vesicoureteral reflux vary dependent on the cause of VUR in your child.
When a child has primary VUR, it means that one or both of the child’s ureters, the tubes that carry urine from the kidneys to the bladder, didn’t develop properly. The ureter is too short, so the valve between the bladder and ureter that normally closes to prevent urine from flowing backward doesn’t shut the way it should.
Primary VUR is the most common kind of VUR and tends to run in families. VUR is present in about 30% of siblings with VUR1, and in up to 50% of children whose mothers had VUR.2 A child may outgrow it when the ureters lengthen and straighten during the growth process. This site provides more information on the chances of outgrowing VUR.