Stinky urine may signal bladder infection in kids

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Your child's stinky urine may be more than just unpleasant: A new study suggests kids with terrible smelling urine should be checked for a urinary tract infection.

According to researchers, only a handful of studies have looked at stinky urine and whether it was a symptom of a urinary tract infection (UTI), but the results were mixed.

"I didn't believe it was that reliable," said Dr. Marie Gauthier, the study's lead author from CHU Sainte-Justine in Montreal.

According to the results of Gauthier's study, it may not be.

The new study is based on 331 children between the ages of one and 36 months, who were suspected of having a UTI and had a urine test at the emergency room between August 2009 and April 2011.

The parents or people who brought the child into the ER filled out a questionnaire about the child's medical history and questions about what happened over the previous two days, such as if the child took antibiotics and if their urine smelled "offensive" or "stronger than usual."

Overall, 51 kids -- about 15 percent -- were diagnosed with a UTI. The parents of about 57 percent of those said their children had stinky urine over the previous two days -- enough to show a link.

But, 32 percent of the parents of children who didn't have UTIs also reported stinky urine.

"It is associated with a urine infection, but the association isn't that strong," Gauthier told Reuters Health. "To have stinky urine in itself isn't proof of urine infection. Not at all."

The researchers write in the journal Pediatrics it could still be useful for doctors and nurses to ask about a child's urine odor if they suspect a UTI.

The researchers also found that girls were more likely to have UTIs, as were kids who suffered from a condition in which urine flowed backward from their bladder into their upper urinary tract.

Even after accounting for those kids, the researchers said stinky urine was still linked to being diagnosed with a UTI.

While the study could not say why the urine of those with a UTI was stinky, the researchers write that it might be from bacteria.

As for the stinky urine of children without a UTI, Gauthier said it could be from dehydrated kids whose urine is concentrated even though they did not find a link between the two.

Watch out for a fever 

The researchers note that their study did have some limitations. Specifically, the presence of stinky urine was reported by the parents and "offensive" or "stronger" smells may mean different things to different people. The number of kids with a UTI was also small, and the study lacked a control group.

Dr. Nader Shaikh, a professor in the department of pediatrics at University of Pittsburgh School of Medicine in Pennsylvania, told Reuters Health that parents should watch if their children have a fever.

"The main thing to watch out for is a fever. That can be the only sign of a urinary tract infection," said Shaikh, who was not involved with the new study. He added that children with stinky urine should also be checked.

As Gauthier pointed out, although they determined the evidence is not strong enough to use urine smell as a way to diagnose UTIs, "If the urine is stinky, the risk of having a urine infection is a little bit higher."