Catheterisation and supra pubic urine aspiration factsheet


Some illnesses and infections can only be found by testing a sample of urine. 

Urine is also known as wee. It is a mix of water and a waste product called urea. Urine is made by the urinary system.

The urinary system includes:

  • the kidneys – the organs that filter waste from the blood, turning it into urine or wee
  • the bladder – where urine is stored
  • the urethra or urinary tract – the tube that takes urine out of the body.

It can be difficult to get a good, clean sample of urine from babies and children. This is because they are not always able to control when they urinate, especially when they are wearing nappies.

There are two common ways to collect a urine sample from babies and children. 

  1. catheterisation - when a thin, plastic tube is inserted into the urethra and up into the bladder to drain the urine out.
  2. supra pubic urine aspiration – most used for very young babies, when a very fine needle is inserted into the lower stomach area, through to the bladder.

Your child’s doctor will let you know which collection method is best for your child.

 Before the test

Your child will need to have a full bladder before the sample is taken. 

They may need to: 

  • drink some water
  • have a scan done of the bladder to see how full it is.

 During the test


To insert a catheter, a doctor or nurse will:

  1. clean around your child’s penis or vulva, where the opening of the urethra is 
  2. cover the catheter in a slippery gel called lubricant
  3. gently insert the tube into the urethra and up into the bladder
  4. wait for enough urine to drain out of the catheter
  5. gently remove the catheter from the urethra.

Supra-pubic urine aspiration

To do a supra-public urine aspiration, a doctor or nurse will:

  1. apply a numbing cream to the lower belly
  2. clean the lower belly, where the needle will go
  3. insert the needle and quickly collect the urine
  4. remove the needle.

 After the test

Once the urine is collected, it is sent to a specialist doctor for testing.

Some results will come back quickly, and others might take a few days. 

Your child’s treatment team will let you know when results come back, and what kind of treatment or further tests your child might need.


Supporting your child

Getting a urine sample can be uncomfortable and distressing for children as they: 

  • are usually feeling unwell
  • need to stay still for the procedure
  • may feel anxious or distressed about needles and medical procedures
  • may feel anxious or distressed about having a procedure on their private body parts
  • will feel some discomfort from the catheter and slight pain from the needle.

Give your child support and reassurance during the procedure by:

  • explaining what is happening and why the test is being done in simple words, even if they are very young and not speaking yet
  • asking the doctors and nurses to talk to your child directly during the procedure
  • giving a comforting touch, like holding your child’s hand or stroking their hair
  • singing a song or telling a story.

Let your child’s treatment team know If you cannot stay with your child during the procedure. They will arrange for another team member to stay and support your child instead.

Last updated Monday 29th April 2024


This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2024