Urinary reflux / VUR (vesico-ureteric reflux)

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Key points to remember

  • urinary reflux (vesico-ureteric reflux) is the abnormal flow of urine back up the tubes (ureters) to the kidneys when a child wees
  • if a baby or child has urinary reflux, they may be at risk of UTIs (urinary tract infections); recurrent UTIs may cause scarring and damage to their kidneys
  • it is important to watch out for the signs of a UTI in your child with urinary reflux
  • if you suspect that your child may have a UTI, go to your GP (general practitioner) for a urine test 
  • in most children the problem is easily managed and resolves as the child grows

It may help to read this fact sheet in conjunction with the following fact sheets on this website:

What is the urinary tract and how does it normally work?

The urinary tract is the kidneys, ureters, bladder, and urethra.

The kidneys filter and remove waste and water from the blood to produce urine. The urine travels from the kidneys down two narrow tubes called the ureters. The urine is then stored in the bladder.

When your child wees, urine flows out of the body through the urethra, a tube at the bottom of the bladder. The opening of the urethra is at the end of the penis in boys and in front of the vagina in girls.

Urinary tract front
Urinary tract side male
Urinary tract female side
Figure 1. Front view of urinary tract
Figure 2. Side view of male urinary tract
Figure 3. Side view of female urinary tract

See Acknowledgements for the above graphics.

What is urinary reflux?

Urinary reflux (vesico-ureteric reflux) is the abnormal flow of urine back up the ureters when a child wees. This can happen because the ureters may not close off when urine is being squeezed out of the bladder when your child wees. Normally when the bladder empties, all the urine flows out of the bladder through the urethra.

There are different degrees of severity of urinary reflux, graded from one to five. Grade one is the mildest form, while grade five is the most severe.

normal kidney, ureter, and bladder

grade I vesicoureteral reflux

grade II vesicoureteral reflux

Normal kidney, ureter, and bladder Grade I urinary reflux:
urine (shown in blue) refluxes part-way up the ureter
Grade 2 urinary reflux:
urine refluxes all the way up the ureter

grade III vesicoureteral reflux

grade IV vesicoureteral reflux

grade V vesicoureteral reflux

Grade 3 urinary reflux:
urine refluxes all the way up the ureter with some widening (dilatation) of the ureter and the part of the kidney where urine collects (calyces)
Grade 4 urinary reflux:
urine refluxes all the way up the ureter with marked widening of the ureter and the part of the kidney where urine collects
Grade 5 urinary reflux:
massive reflux of urine up the ureter with marked twisting and widening of the ureter and the part of the kidney where urine collects

See Acknowledgements for the above graphics.

What are the signs and symptoms of urinary reflux?

  • urinary reflux does not cause any symptoms in affected babies or children
  • the most common sign of urinary reflux is a UTI (urinary tract infection)
  • if your child has urinary reflux, it is important to watch out for the signs of a UTI in your child
  • if you suspect that your child may have a UTI, go to your GP (general practitioner) for a urine test (see When should I seek help? in the UTI fact sheet)
  • another sign of urinary reflux is a dilated (widened) urinary tract detected on ultrasound scan; this can sometimes be diagnosed before a baby is born when the mother has an ultrasound scan in pregnancy

See the following fact sheets on this website:

How is urinary reflux diagnosed?

There are a variety of tests your doctor may request to diagnose urinary reflux and assess the condition of your child's kidneys and drainage tubes:

  • MCU (micturating cysto-urethrogram) - see the MCU fact sheet on this website
  • renal ultrasound scan  - see the Renal ultrasound scan fact sheet on this website
  • DMSA renal scan - see the DMSA renal scan fact sheet on this website

What are the complications of urinary reflux?

  • urinary reflux may increase the chance of your child getting UTIs (urinary tract infections) because of the faulty drainage of urine
  • urinary reflux alone does not usually cause kidney damage but recurrent UTIs in children with urinary reflux may cause kidney damage and scarring and can affect how well the kidneys work.

Only a small proportion of children with urinary reflux develop significant kidney problems. In most children the problem is easily managed with appropriate treatment and monitoring.

See the following fact sheet on this website:

What treatment is required if my child has urinary reflux?

Urinary reflux usually resolves by itself as the child grows, especially if it is mild.

The treatment is aimed at preventing UTIs (urinary tract infections) while your child is young, when UTIs can cause damage to the kidneys. Sometimes, a small dose of antibiotics is prescribed at night to prevent UTIs until the urinary reflux improves or resolves by itself. In most children , no treatment is necessary and your child's doctor will monitor the growth and health of your child kidneys with scans. This will depend severity of reflux your child has.

Regular urine tests may be necessary to make sure there is no infection present. If your child develops any symptoms of a UTI while on antibiotics, you should take them to your GP (general practitioner) for an immediate urine test.

See the following fact sheets on this website:

Will long-term follow-up be needed?

In most children, urinary reflux resolves completely in childhood and they have no future problems. 

Urinary reflux may be associated with abnormal development of the kidneys resulting in a condition known as “dysplasia”   Kidney dysplasia causes reduced function in the affected kidney. Children with reflux and dysplasia will need to have their blood pressure measured every year.

Where to go for more information

Kidney Kids  kidneykids.org.nz/
Kidney Kids is a group of New Zealand parents and children, who are dealing with kidney issues, and who get together to share problems, solutions and good times. Kidney Kids has support groups and contacts throughout New Zealand.
Physical address: 33 Vestey Drive, Mount Wellington, Auckland 1060
Postal address: PO Box 13 732, Onehunga, Auckland 1643
Phone: 64 9 574 2382
Freephone: 0800 215 437
Fax: 64 9 574 2378
Email: admin@kidneykids.org.nz

New Zealand Kidney Foundation  www.nzkidneyfoundation.co.nz/
The New Zealand Kidney Foundation provides education and support in the recognition of the symptoms of kidney disease; provides resource information concerning the treatment and management of patients with kidney disease and liaises with and supports patient support groups. The website provides details of patient support centres in New Zealand.
Physical address: 24 St Asaph Street, Christchurch
Postal address: P O Box 139, Christchurch
Freephone: 0800 KIDNEY / 0800 543 639
Phone: 64 3 353 1242
Fax: 64 3 374 2176
Email: info@nzkidneyfoundation.co.nz

Acknowledgements

This fact sheet has been adapted from:
  • Paediatric Outpatient Department. Christchurch Hospital. Canterbury District Health Board. 2002. Urine infections and ureteric reflux.
  • Children’s Unit. Waikato District Health Board. 1997. Your child with urinary reflux.
Graphics of the urinary tract reproduced from NKUDIC (the National Kidney and Urologic Diseases Information Clearinghouse), United States. (These images are in the public domain; reproduction permitted).
 
Graphics of a normal kidney, ureter and bladder and grades 1 to 5 reflux reproduced from Texas Pediatric Surgical Associates website (no longer available) with permission.
This page last reviewed 27 March 2013
© Paediatric Society of New Zealand and Starship Foundation 2005 – 2014
Printed on 30 July 2014. Content is regularly updated so please refer to www.kidshealth.org.nz for the most up-to-date version
Content endorsed by the Paediatric Society of New Zealand