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  • Post last modified:May 24, 2022
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Sometimes, a baby’s pee smells bad, or has a strong smell. This is more common in the morning, but can happen at any time. Why is this? Let’s go through a few different reasons and what to do about it. 

baby's pee smells bad

Mom’s Question:

My 9-month-old baby’s pee smells bad, especially the nappy I change in the morning.

She pees frequently and she drinks 19ozs of milk a day and has water at every mealtime. Her pee is not dark in color and she doesn’t seem to be in any discomfort, but I am concerned with this sudden change in smell.


Reasons Why a Baby’s Pee Smells Bad

It is good that you pay attention even though your baby doesn’t seem to be ill, sinces sometimes a baby’s pee can smell strong because they have a Urinary Tract Infection. However, in such cases it is usually accompanied by fever and a lot of crying.

Here are some possible reasons for smelly pee in babies:

1. Normal!

It is possible that your baby’s pee smell is completely normal, and just smelling a bit more now than when she was younger. A lot of what you write point in that direction – she is drinking enough fluids, she is otherwise healthy, and her urine is pale. So chances are that this is simply the way her pee smells right now.

The fact that the first diaper in the morning is the most smelly one is completely normal. The diaper hasn’t been changed for several hours and can certainly begin to smell even if the baby is completely healthy.

 2. Something she or you ate

I don’t know if you breastfeed, but if you do, changes in your diet can actually affect the smell of your baby’s urine. I have read reports that breastfeeding moms that take antibiotics, or that eat lots of aspargus or garlic sometimes notice changes in their babies urine.

Similarly, if you have introduced new foods to your baby recently, this could certainly affect the smell of her urine.

3. A Urinary Tract Infection

As I mentioned above, smelly urine can also be a sign of a urinary tract infection (UTIs). In most cases, this would not be the only symptom. An unexplained fever is actually a more common symptom. (Read more about signs of urinary tract infections in babies here.)

A Canadian research study actually examined the correlation between smelly urine and UTIs and found UTIs among 57% of the babies whos parents reported smelly urine. So, this can certainly indicate a urineare tract infection, but it is not a certain sign at all.

It should be noted that urinary tract infections are much more common among girls than boys, so it would be wise to rule this out for your daughter.

4. Too little fluid

I don’t think this is relevant for your situation, but a strong smell of a baby’s urine can, of course, also be a sign that they are getting too little fluids. This could, for example, happen in hot weather or if the baby has been sick. In such a case, the urine would also become darker.

What to do?

If this smell is still bothering you I would go to the Dr and get it checked out to rule out a UTI and try to narrow down what is causing the smell. Write down what your baby eats and drinks for a day or two before you go – or of course what you eat and drink if you breastfeed.

If your baby doesn’t have any other symptoms she is probably just eating something that’s making it smell bad.

Your baby seems to be getting enough fluids so I would try giving your baby a little bit of cranberry juice for babies.

I hope this helps,


More About Baby Urination

Find comments below.



Nov 30, 2019 1st time momby: Newman

I have a nine and half month old and we experienced this as well starting about 7 months, which is also when she started teething. I talked to a few other moms, including my own and was told it was a normal side affect of teething, but doesn’t really go away after the teething is finished, but the smell does get a little better from what i have noticed.

From my research i have found there can be a few other causes as well-Change in formula or from BM to formula, starting new foods or starting to eat more solid foods/finger foods, colds and/or other sinus problems, were the main ones i found.

As long as she doesn’t seemed bothered by it and she is still urinating as usual i wouldn’t worry about it, but if it does become dark in color or her belly starts to bother her i would call her doctor.

Apr 17, 2020 baby pee smells
by: amanda
hi there I would definitely get your baby checked if his or her pee smells weird. even if u think it might be different foods or drinks. no get it checked my son’s pee started to smell at 4weeks old and it was a weird smell and even my nurse told me he was fine but I knew something wasn’t write he didn’t have a fever but he was really bad with his feeds he would fight every bottle and do a big spew almost after every bottle he was really unsettled so I took him to the doctor and they told me take him straight to Westmead children’s hospital so I did turns out he had a uti. the next morning we were back for a ultrasound to check his kidneys turns out he had grade 1 kidney reflux so they put him on antibiotic’s so then we had to go back when he was 3months old and then bad news hit it had gone from grade 1 to grade four kidney reflux and the highest it gets is grade 5 so it was pretty bad .
so far his kidneys have gone down from being swollen but no scaring yet.he is now 7months old and still on antibiotic’s we go back when he is 1 to see if it is still there if it is I hope they will fix it. so yeah I think no matter what anyones says you should always go to the doc and get it looked at its better to be safe then sorry

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