The Nose Knows—UTIs and Your Baby

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Is your baby running a fever? You may want to open up that diaper and take a sniff…

The Scoop

The next time your baby spikes a fever out of the blue, you may want to give her diaper a whiff to check for any unusual or pungent odors. Why the sniff test? According to a study from researchers in Canada, malodorous (aka smelly) urine combined with a fever may be a sign that a child has developed a urinary tract infection (UTI).

In the study, researchers in Montreal surveyed parents of 331 children between the ages of 1 and 36 months of age who had brought their child to a local ER because the child had a fever. While waiting to be seen, parents completed a health questionnaire, including two questions about whether their child's urine smelled stronger than normal or somehow unusual. When the results were tallied, almost 60 percent of kids whose parents reported smelly urine tested positive for a UTI. Among children whose parents indicated nothing unusual about their child's urine scent, 32 percent had a UTI.

"If the child has fever and at the same time his urine smells stronger than usual, the risk of having a urine infection is a little bit increased compared to a child not having smelly urine," Dr. Marie Gauthier, a pediatrician at Sainte-Justine University Hospital Center in Montreal and the study's lead author, tells NPR News.

Dr. Gauthier says that foul-smelling urine when a child has a UTI is the result of ammonia produced by bacteria. By the time the smell is noticed, it may mean that bacteria have entered the urinary tract and multiplied to the point of causing an infection.

Other symptoms of UTI in children can include fever, loss of appetite, nausea, vomiting, and diarrhea, or just not seeming healthy without signs of a runny nose or other obvious cause for discomfort. A child's pediatrician can easily for a UTI with a urinalysis. Like other bacterial infections, UTIs in infants and young children are typically with treated with antibiotics.

Your Baby

Got a smelly diaper on your hands, but not sure it's a UTI? Many other things can make urine stronger smelling than normal, including diet, the time of day at which the smell test is conducted, and how well hydrated a child is. It's also true that smell is a very subjective thing—what is unusual or offensive to one parent's nose might not be to another. To put your mind at ease, when in doubt, ask your doc about this—even if it is just to get a second opinion on what's behind your baby's stinky diaper.