- Hydronephrosis: The conditions occurs where there is a blockage or deficient valve at work in the urinary tract. When this happens, the tube connecting the kidney to the bladder becomes blocked, causing the kidneys to swell. It occurs during fetal development in about 1 in 100 pregnancies. The causes of hydronephrosis are many, and in some instances the kidney(s) may become damaged unless the primary cause is addressed and treated.
- Undescended testicles (cryptorchidism): This is the most common birth defect of the genitourinary tract in male babies. The testicles are two small round organs usually located in the scrotum in males. Normally, the testicles develop in the abdomen in the male fetus and descend (move down) to the scrotum before birth. If a baby is born with undescended testicles, the testicles will usually descend within 6 months after birth. However, in some cases, the testicles do not descend, but remain in the abdomen or groin area.
- Hypospadias: This condition only affects male infants. It results when the opening of the urethra (where the urine exits the body) is located on the underside of the penis, instead of at its tip. It occurs in about 5 in 1,000 male infants born in the United States. It is one of the most common urological anomalies. Boys who are born with hypospadias may also have a curved penis or undescended testicles. They may experience difficulty when they urinate, due to difficulty in directing the stream of urine.
- Spina bifida, or “cleft spine”: This birth defect occurs when the brain, spinal cord and/or meninges do not develop completely during fetal development. The meninges are a protective covering that surround the spinal cord. There are four different types of spina bifida, ranging from mild to severe. People with the more severe forms can experience partial or complete paralysis below the spinal opening. This can result in bladder or bowel dysfunction as well as problems with the lower extremities.
- Vesicoureteral reflux (VUR): This condition refers to the abnormal upward flow of urine from the bladder to the upper urinary tract. Urine that is produced by the kidneys normally is stored in the bladder and flows out of the body through a tube connected to the bottom of the bladder. With vesicoureteral reflux, urine flows back or refluxes into one or both ureters, the narrow tubes that connect the bladder to the kidneys. Sometimes the urine flows back to one or both kidneys.
If only one ureter and kidney are affected, it is called unilateral reflux. If both are affected, it is called bilateral reflux. VUR occurs more often in babies and young children, but older children and adults can also have it.
- Bladder exstrophy: This is a rare congenital abnormality in which the bladder and associated structures are turned inside out. The rear part of the bladder wall is turned outward (exstrophy) through an opening in the abdominal wall. Urine flows out of the opening into the lower abdomen. Bladder exstrophy has various degrees of severity. The least severe form occurs when there is a defect in the urethra, the tube that carries urine out of the body. Classic bladder exstrophy occurs when there is an opening from the top of the bladder through the urethra and the tip of the penis (in male children). The exact cause of the condition is not known. Complications may include bacterial urinary tract infections and kidney damage. Scarring of the kidneys may result in high blood pressure and kidney failure.
- Prune belly (Eagle-Barrett syndrome): This is a rare genetic disorder that mainly affects male children. There is a complete or partial absence of abdominal (stomach) muscles, causing the belly to appear wrinkled or prune-like. Associated malformations of the urinary tract may include an enlarged bladder or obstruction (blockage) of the neck of the bladder. Other defects can include widening of the ureters and undescended testicles. The condition can cause urine to accumulate in the ureters or kidneys and flow backward from the bladder to the ureters.
- Posterior urethral valve (PUV) disorder: This congenital condition is caused when there are extra flaps of membrane in the back of the urethra. It occurs only in male babies and causes blockage of the urine flowing through the urethra. PUV causes a backflow of urine to the bladder, possibly causing its muscular wall to thicken. The bladder may become enlarged. When urine flows up through the ureters into the kidneys, the ureters and kidneys may become damaged.