Bladder Outlet Obstruction

​​Bladder outlet obstruction or BOO is a problem that develops in the foetus (unborn baby) during pregnancy. It occurs when the urethra (duct by which urine flows out of the body) is completely or partially blocked. It is more common in male children than female children.

Blockage of urine outflow may cause it to flow backwards which can affect all of the organs including the bladder, ureters and kidneys. These organs become filled with urine and swell, causing damage.​