Urine tests

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 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?