Hydronephrosis affects up to 2 percent of all children, according to a report from the University of California San Francisco Children's Hospital (UCSF). This condition is a swelling of the kidneys with urine, caused by an obstruction in the urinary system.
Most cases involve partial blockages, and clear up by themselves. But severe cases can cause pain, bleeding, infections and kidney damage.
Ultrasound tests in pregnancy can detect hydronephrosis before the child is born. In fact, this is the most common prenatally diagnosed malformation. Doctors may want to prescribe antibiotics for the child within the first few days after birth to prevent urinary tract infection. At one to three months of age, medical imaging can show which children need surgery.
Fetal surgery is a more controversial option. Severe cases of fetal hydronephrosis may be a sign of future urological problems including poorly compliant bladder, sphincter dysfunction, urinary tract infections, and even kidney failure. Thus, in the early 1980's, surgeons began operating on fetuses to correct the obstruction. The initial surgeries were performed as traditional open surgeries. Unfortunately, this treatment produced preterm labor with its own risks, and was discontinued.
The technique of transuterine endoscopy was developed at UCSF in an attempt to make fetal surgery safer. In 2004, three urologists recommended “fetal surgery should continue to be performed only for carefully selected cases at centers that are equipped with a multidisciplinary health care team committed to ongoing, well-designed research protocols” (Ref. 1).
Both UCFS and Children's Hospital Boston have provided information about hydronephrosis and fetal surgery on their web sites (see below).
In most cases surgery will be reserved until after birth. Texas Pediatric Surgical Associates provides details on its web site. http://www.pedisurg.com/PtEduc/Antenatal_Hydronephrosis.htm
Hydronephrosis is not a disease in itself, but a condition that indicates something is obstructing the flow of urine. In adults, kidney stones and injuries are common causes. Hydronephrosis may also occur in pregnancy without a known cause. A urologist can recommend appropriate treatment.
Swana HS et al, “Prenatal intervention for urinary obstruction and myelomeningocele”, Int Braz J Urol. 2004;30:40-8.
University of California at San Francisco Children's Hospital:
Children's Hospital Boston:
Texas Pediatric Surgical Associates:
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.