Urine Tests

Urine Tests

Testing a sample of your child's urine (wee) is the only way to know for sure if they have a UTI (urinary tract infection).


Why is my child having a urine test?

Testing a sample of your child's urine (wee) is the only way to know for sure if they have a UTI (urinary tract infection) or any other abnormality of the kidneys. You might like to read this page together with the UTI page.

How are urine samples collected?

Children who are out of nappies and who can wee when asked will normally provide A MSU (mid stream urine sample).

In younger children who are in nappies and cannot wee on request, an MSU is usually not possible. Several methods can be used:

  • 'clean catch'
  • bag collection -  if a UTI is suspected this is the least reliable method
  • catheter sample 
  • SPA (suprapubic aspirate) 

For all urine samples, regardless of how they are collected, the following apply:

  • on the container write your child's first name, surname, date of birth, and the date and time you collected the sample
  • it is important that the urine sample is fresh when tested so try to take it to the laboratory within 2 hours or put it in the fridge (not the freezer) until you can deliver it

MSU (mid stream urine sample)

  • your child needs to start passing urine into the toilet and then you catch some of the middle part of the urine stream in a sterile container (from your doctor); you don't need a large amount - your child can then finish passing urine into the toilet

'Clean catch'

  • this involves 'catching' a sample of clean urine from an infant or young child as they wee
  • give your infant a drink or breast feed to help fill the bladder
  • clean your child's genital area with soap and water
  • leave your child's nappy off and wait for them to wee and quickly catch a small amount in a sterile container (from your doctor)
  • it can be difficult to time catching a wee; you may need to make several attempts -this can be time-consuming and often not practical when infants are unwell
  • a clean catch is only really practical to do in infants who are not yet mobile and so can lie still on their backs

Bag collection

  • you attach a plastic bag, which has a sticky strip, over your baby's genital area after cleaning very well with soap and water (for boys, the entire penis can go in the bag; for girls, the bag goes over the labia)
  • you can put a nappy on, over the bag
  • urine collects in the bag when your baby wees
  • sometimes it can take several attempts to get some wee
  • transfer the urine sample from the bag into the sterile container (from your doctor)
  • don't leave the bag on overnight - if your child has not passed urine after 4 hours, put on another bag
  • a bag urine sample is often contaminated by germs from the skin; this can make it look like your child has a UTI (urinary tract infection) even if they don't really
  • bag collection is the  least reliable way of collecting a urine specimen in an infant
  • if the result indicates a possible UTI, your child will need a clean urine sample taken directly from the bladder to confirm the result (see Clean urine collection methods below)

Clean urine collection methods

Catheter samples and SPAs (suprapubic aspirates), also called 'bladder taps', are a way of getting urine directly from the bladder. Unlike the bag urine test, there is little chance of contamination of germs from the skin. Clean urine collection methods are the best way to accurately diagnose a UTI (urinary tract infection).

Catheter sample

  • a doctor or nurse passes a fine plastic tube (catheter) into the urethra and bladder so that they can collect a urine sample into a sterile container - the urethra is the tube from which urine passes out of the bladder
  • your child needs to lie down with their ankles held together to make sure the catheter goes in cleanly - babies and young children may not like being held in this position, but it only takes a few minutes
  • the test is uncomfortable - you should reassure and comfort your child during the test

SPA (suprapubic aspirate)

  • your child lies down on their back and needs to be held still
  • a doctor puts a small needle through the skin of the lower part of their tummy (abdomen), and into the bladder
  • urine is collected straight from the bladder via the needle into the syringe
  • SPAs are a very safe test and problems are rare
  • in terms of pain for your child, it is similar to having a blood test

How are urine samples tested?

Urine samples are first usually tested with a 'dipstick' (test strip) straightaway by your doctor or nurse. This can provide clues about whether your child may have a UTI (urinary tract infection), but a final diagnosis can only be made by sending the urine to the laboratory for a 'culture' to be done. A culture is where the germ (bacteria) is grown in a special gel. This helps to identify what kind of germ it is. Doctors can then decide which antibiotics to use to kill it. Culture results may take 24 to 48 hours.
If the dipstick test suggests a UTI, then treatment is usually started before the culture results are available. The diagnosis and treatment may be changed once the culture results are available from the laboratory.

The content on this page has been adapted from:

  • The Royal Children’s Hospital (Melbourne) Kids Health Info for parents: Urine tests.
  • Paediatric Outpatient Department. Christchurch Hospital. Canterbury District Health Board. 2002. Urine infections and ureteric reflux.
  • Children’s Unit. Waikato District Health Board. 1999. Urinary tract infections.

This page last reviewed 30 August 2018.

Call Healthline on 0800 611 116 any time of the day or night for free health advice when you need it