Inside Pediatrics Magazine Fall/Winter 2025

DIVISION ROUNDS

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UROLOGY

A new protocol for kidney tests in spina bifida patients

hydronephrosis had only about a 25% sensitivity for identifying children with signs of chronic kidney disease in the UMPIRE study and 24% in the NSBPR cohort. That means kidney damage in three out of four children was going undetected. The poor sensitivity held even when researchers looked only at severe hydronephrosis, which had an even worse sensitivity rate—just 6% to 11%. “The renal ultrasound by itself wasn’t all that good,” Joseph said, “but that didn’t surprise us.”

A new study from Children’s of Alabama urologists Stacy Tanaka, M.D., and David Joseph, M.D.—along with other kidney experts from around the country—shows that ultrasound alone is not enough to assess kidney health in spina bifida patients. This is important because people with spina bifida tend to develop end-stage renal disease up to 20 years earlier than the general population, so keeping a close watch on their kidney health from a young age is crucial. Current guidelines from the Spina Bifida Association (SBA) recommend annual screening with ultrasound to look for hydronephrosis—a condition in which the urine backs up into one or more kidneys—as a sign of kidney function and blood tests, such as serum creatinine, to measure overall kidney health. But with kids, Tanaka said, “the practice pattern was that a lot of people were only doing renal ultrasound.” “We basically use ultrasonography as a reflection of renal function,” Joseph added, but few, if any, studies had assessed its accuracy in determining renal function. In the study, investigators used data from the National Spina Bifida Patient Registry (NSBPR) and UMPIRE, a urologic protocol, to manage and preserve initial renal function in young children with spina bifida. The two registries include data on 2,500 children ages 1–18 with myelomeningocele, the most severe form of spina bifida. All had undergone an ultrasound and blood test within six months to determine estimated glomerular filtration rate (eGFR), a marker of kidney health. The results were striking: Ultrasound-based detection of

Ultrasound-based detection of hydronephrosis has only about a 25% sensitivity 25 %

Children with spina bifida have undetected kidney damage 3 out of 4

The findings challenge current practice and suggest that blood tests measuring kidney function should be routinely performed alongside ultrasound, not just when ultrasound results look concerning, as some clinicians practice. “The ultrasound is very helpful and important,” Joseph said, “but you need to recognize that it may not be telling you about renal function or injury to the kidney.” The findings have already changed practice at Children’s, where all kids with spina bifida now receive both tests during kidney health screening.

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