The ultimate baby pee guide: Smell, colour, frequency, what’s normal and when to worry

As a new parent, one thing you'll find yourself doing regularly - apart from just feeding, is changing your newborn’s nappies. Newborns tend to feed every 2-3 hours so it's understandable that it has to come out the other end as baby poop or, of course, wee.

While it might not be the most talked-about topic, understanding the colour, smell, and frequency of baby pee can give you valuable insight into their hydration and overall health.

It's also worth paying attention to the frequency of their urine. Typically six to eight wet nappies a day is a sign that your baby is getting enough to drink. Paying attention to these little details can help you keep your baby happy, healthy and hydrated.

While changes in baby pee can be confusing or even alarming, most are normal and easily explained. To help you decipher your baby's pee, we've included clear explanations, charts, and visual aids, to give you a better understanding of what different baby pee colours mean, how often your baby should be weeing, what their urine smell might tell you, and when to speak to the GP or health visitor.

Baby pee colour

Just like adults, healthy baby wee colour is usually light to dark yellow. This colour may change from time to time, however, if your baby’s pee smells particularly strong or unusual, it could be worth consulting your healthcare provider to ensure everything is okay. Sometimes subtle signs can be early indicators of dehydration or infection in newborns.

Check out our baby pee colour chart below for a quick indication of what your baby’s pee colour means

Light to dark yellow baby pee

Light yellow pee is a good, healthy sign. Dark yellow pee could indicate your baby is a little dehydrated and needs to consume more milk, and dark yellow pee could also be a sign that they are jaundice.

Pink baby pee

This is highly concentrated pee (not to be mistaken with blood). If your baby is peeing a lot there’s no need to worry, however if this colour persists, contact your healthcare provider. If your newborn girl has a pinkish stain in her nappy it could indicate blood in her pee (According to Healthychildren.org this only applies to girls, as the mum's hormones affect the baby's uterus.) It sounds alarming but usually there's nothing to worry about. Blood in a newborn's urine is usually temporary and caused by the mum’s hormones. If these pink spots continue to appear, or her pee is consistently pink after she turns one week old, contact your healthcare provider.

Orange, red or brown baby pee

The medical term for blood in urine is hematuria and this is not normal for either boys or girls (after one week old) and usually indicates a problem. If you spot this, contact your child’s healthcare provider.

Red, brown or cloudy baby pee

This could be a sign that your baby is suffering from a UTI or kidney infection. If this occurs, contact your child’s healthcare provider immediately and more so if there’s also blood in it.

Red-brown baby pee

This colour is also referred to as ‘brick-dust’ as it looks a little like brick-dust has been sprinkled into your baby’s urine. It can often be mistaken for blood. It’s actually urate crystals (a by-product of concentrated urine) and should go once your baby has consumed more fluids.

Remember, the times to be most concerned about your baby's pee is:

• If it presents orange, brown or red tints - this could be a sign of blood.

• If your baby isn't peeing at all (or under the normal amount)

• Your baby's pee smells sweet.

Contact your healthcare provider if any of these occur or if you have any other concerns about your baby's urine.

How often should my baby pee?

If your baby is peeing a lot, it’s usually a good sign and means your newborn is getting enough food. If your baby is drinking enough milk, then you can expect six or more wet nappies a day during your baby’s first month.

Baby is peeing a lot - what does it mean?

If you notice your baby is peeing more than usual, such as more than once every hour, then it's time to contact your child’s healthcare provider. It could be a sign of a urinary tract infection (UTI). Other signs can include crying when they pee, having a fever, be irritable and not wanting to feed.

Baby isn't peeing much – what does it mean?

If you notice your baby is not peeing very often or fewer than four times a day, they could be ill, have an infection or be dehydrated. If it's very hot, it's normal for urine to sometimes decrease and could drop by half. Once this passes, it should return back to normal.

On the other hand, if your baby isn't feeding well, this would be another reason why they might not be peeing very much. It can be hard to judge if you're breastfeeding, so look out for other signs i.e if they’re oversleeping or if they seem lethargic. If your baby doesn't pee within 6-8 hours, contact your healthcare provide immediately.

How often should you change your baby’s nappy?

You're going to be getting through a lot of nappies so stock up! The NHS advise to change your newborn's nappy whenever they have done a wee or poo in order to keep them comfy and prevent nappy rash. Yes that is a lot of nappies! They say "In the beginning expect to change your baby's nappy around 10 to 12 times a day. When your baby is a bit older, you'll probably change them 6 to 8 times a day."

In general, if your baby has four to six wet nappies a day and they seem happy enough, then so should you. If however your baby has a lot more or less and you notice changes in their behaviour, there may be something else at play.

How many nappies per day?

The NHS says: "In the first 48 hours, your baby is likely to have only 2 or 3 wet nappies. Wet nappies should then become more frequent, with at least 6 every 24 hours from the fifth day onwards." It is also advisable to change your newborn's nappy whenever they have done a wee or poo in order to help prevent nappy rash. Yep that adds up to a lot of nappies!

In general, if your baby has four to six wet nappies a day and they seem happy enough, then there should be nothing to worry about. However, if your baby has a lot more or less than this, and you notice changes in their behaviour, there may be something else at play.

Baby’s pee smells – what does it mean?

1). Strong smelling urine

Smelly urine can certainly take the cute factor down a few notches! If your infant's urine smells like strong ammonia or has a strong fishy odour, this could be a sign that your baby has an infection or a bacterial infection such as a UTI (urinary tract infection). It can lead to illness if left untreated, so contact your healthcare provider if you think it could be something serious. However, a strong pee smell doesn’t always indicate an infection, if it is highly concentrated with a dark yellow colour, your little could be dehydrated.

If your baby has a UTI they may also:

• be irritable

• have a fever

• be peeing a lot more than often

• showing discomfort whilst peeing

Signs of an infection could include:

• blood in your baby’s pee

• pee that looks cloudy

• a strong smell in your baby's urine

2). Sweet-smelling urine

If the baby wee smells a little like maple syrup, it may indicate a serious illness called Maple Syrup Urine Disease (MSUD) – yes, that's a thing! The NHS says it's an inherited condition; "It means the body cannot process certain amino acids (the 'building blocks' of protein), causing a harmful build-up of substances in the blood and urine." Signs for MSUD usually occur within the first few days of birth, or between five months and seven years. Sweet-smelling urine can also be a sign of diabetes. Both of these are serious conditions, so if your baby’s pee smells sweet contact your healthcare provider.

3) Breastfed vs formula fed pee

Formula-fed babies often have a slightly stronger smell in their pee and it's usually darker compared to breastfed babies and comes down to how formula is digested. Conversely, breastfed babies' urine has a lighter colour and a less noticeable smell.

Signs of dehydration in babies

If your baby’s pee smells strong and is highly concentrated it could be a sign your baby is dehydrated. Parents should keep an eye on how many wet nappies they are changing compared to other days. Look out for strong-smelling pee or a colour that looks dark orange - these can all be indicators of dehydration, as well as sunken fontanelle (the soft spot on their head), a dry mouth, or unusual drowsiness. If you experience any of these symptoms, it's important to seek medical advice.

Other things to look out for

If your baby has a dry nappy overnight, it could be a cause for concern but some babies may occasionally have dry diapers overnight, even at a young age and it is quite normal. As long as they don't exhibit any other signs like dry lips, lethargy, or sunken eyes, as this could indicate dehydration.

If your babies nappy is leaking, it could be the wrong size or they could be wearing it for too long. Try sizing up or down and be sure to change the nappy regularly, especially before bedtime.

Baby pee summary

By now you may better understand that your baby's pee smell and colour can indicate different things. It's worth paying attention to their pee smell and colour when you change their nappy. Pay attention to the number of wet nappies, there should be at least 4-6 wet ones a day or more. A healthy baby has yellow pee - between light and dark. Pink-tinted pee usually means highly concentrated urine, and red, orange, or brown colour pee indicates blood. The smell of their pee can reveal a lot too - it can be strong without any issues, but if it smells really bad, it could be a sign of a UTI.

About the author

Proud aunt to her teen niece, Zara Mohammed is a Digital Writer for Mother&Baby. She has 10 years freelance writing experience creating lifestyle content for various platforms, including pregnancy, women’s health, parenting, child development and child mental health, plus lots of fun seasonal family articles and celebrity news.