Key points about urinary reflux
- urinary reflux is also called vesico-ureteric reflux
- it is the abnormal flow of urine back up the tubes (ureters) to the kidneys when a child does a wee
- if a baby or child has urinary reflux, they may be at risk of urinary tract infections (UTIs)
- repeated UTIs may cause scarring and damage to 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 a health professional for a urine test
- in most tamariki (children), urinary reflux gets better as they grow
It may help to read this together with the following pages.
Urinary Tract Infection In Children
The urinary tract and how it works
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 2 narrow tubes called the ureters. The urine is then stored in the bladder.
When your child does a wee, 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.
An illustration showing the front and side view of the female urinary tract.
Source: KidsHealth
transcribeTranscript
The illustration shows the front view and side view of the female urinary tract.
The illustration's main label is: Female urinary tract
The left side of the illustration has the label: Front view
- Inside her body, there are 2 kidneys.
- Thin tubes called ureters run from each kidney down to the bladder.
- A short tube called the urethra leads from the bladder to the outside.
The right side of the picture has the label: Side view
- In this side view, inside her body, you can see 1 kidney.
- The ureter goes down from the kidney to the bladder.
- he urethra goes from the bladder to outside the body.
Labels point to these parts on both views:
- Kidney
- Ureter
- Bladder
- Urethra
At the bottom left is the KidsHealth logo with the website: kidshealth.org.nz.
An illustration showing the front and side view of the male urinary tract.
Source: KidsHealth
transcribeTranscript
The illustration shows the front view and side view of the male urinary tract.
The illustration's main label is: Male urinary tract
The left side of the illustration has the label: Front view
- Inside the young boy's body, there are 2 kidneys.
- Thin tubes called ureters run from each kidney down to the bladder.
- A short tube called the urethra leads from the bladder to the outside.
The right side of the picture has the label: Side view
- In this side view, inside his body, you can see 1 kidney.
- The ureter goes down from the kidney to the bladder.
- The urethra goes from the bladder, through the penis, to outside the body.
Labels point to these parts on both views:
- Kidney
- Ureter
- Bladder
- Urethra
At the bottom left is the KidsHealth logo with the website: kidshealth.org.nz.
What is urinary reflux?
Urinary reflux is the abnormal flow of urine back up the ureters towards the kidneys when a child does a wee. This can happen because the ureters may not close off when urine is being squeezed out of the bladder when your child does a wee. Normally when the bladder empties, all the urine flows out of the bladder through the urethra.
This illustration shows normal urine flow compared with grade 1 urinary reflux, where urine refluxes partway back up the ureter.
Source: KidsHealth
transcribeTranscript
The illustration shows a young child with a simplified diagram of the kidneys, ureters, bladder, and urethra drawn on the body.
A circle highlights the urinary tract, with dashed lines pointing to 2 enlarged diagrams:
The top diagram is labelled Normal and shows urine flowing in the correct direction — from the kidneys down the ureters into the bladder. Labels read:
- Normal flow of urine
- Urine inside the bladder
The bottom diagram is labelled Grade 1 urinary reflux. An arrow shows urine moving partway back up one of the ureters from the bladder. A label reads: Urine refluxes part way up the ureter.
At the top right is the KidsHealth logo with the website: kidshealth.org.nz.
Urinary reflux can be from grades 1 to 5. Grade 1 is the mildest form, while grade 5 is the most severe.
This illustration shows grade 1 urinary reflux, where urine refluxes part-way up the ureter.
Source: KidsHealth
transcribeTranscript
The diagram shows both kidneys, ureters, bladder, and urethra. A grey arrow shows urine refluxing from the bladder partway up one ureter. The kidneys and calyces look normal. Label: Urine refluxes partway up the ureter.
Parts of the urinary tract are labelled: kidney, calyces, ureter, bladder and urethra.
At the bottom left is the KidsHealth logo with the website: kidshealth.org.nz.
Check some diagrams showing the different grades of urinary reflux.
Signs and symptoms of urinary reflux
Urinary reflux does not cause any symptoms in affected pēpi (babies) or tamariki. The most common sign of urinary reflux is a UTI.
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 a health professional for a urine test.
Another sign of urinary reflux is a widened (dilated) urinary tract. An ultrasound scan can show this. Sometimes, an ultrasound scan in pregnancy can show this before a baby is born.
Diagnosing urinary reflux
There are a variety of tests your health professional may request to diagnose urinary reflux and assess the condition of your child's kidneys and drainage tubes.
See the following KidsHealth pages for information about these tests.
Micturating Cysto-Urethrogram (MCU)
Nuclear Medicine Kidney Scans In Children
Possible complications of urinary reflux
Urinary reflux may increase the chance of your child getting UTIs because of the incomplete drainage of urine.
Urinary reflux alone does not usually cause kidney damage. But, recurrent UTIs in tamariki with urinary reflux may cause kidney damage and scarring and can affect how well the kidneys work.
Only a small proportion of tamariki with urinary reflux develop significant kidney problems. In most tamariki, the problem is easily managed with appropriate treatment and monitoring.
Managing urinary reflux
Urinary reflux usually gets better by itself as your child grows, especially if it is mild.
The treatment aims to prevent UTIs while your child is young, when they can cause damage to the kidneys. Sometimes, the health professional may prescribe a small dose of antibiotics to prevent UTIs until the urinary reflux improves or gets better by itself.
In most tamariki, no treatment is necessary and your child's health professional will monitor the growth and health of your child's kidneys with scans. This will depend on how severe your child's reflux is.
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, take them to a health professional for an immediate urine test.
Will my child need long-term follow up for urinary reflux?
In most tamariki, urinary reflux gets completely better in childhood and they have no future problems.
Urinary reflux sometimes happens with abnormal development of the kidneys resulting in a condition known as dysplasia. Kidney dysplasia causes reduced function in the affected kidney. If your child has urinary reflux and dysplasia, their health professional will measure their blood pressure every year.
Tamariki who have severe reflux and repeated UTIs may also develop kidney damage and need further monitoring.
More information
Kidney Kids NZ is a not-for-profit organisation dedicated to supporting children and young people in New Zealand affected by kidney disease or urinary tract conditions. They provide free emotional and practical support, educational resources, advocacy, community building through events and camps, and connections for both the children and their whānau.
The Kidney Health New Zealand website has information for whānau and health professionals on common kidney conditions in childhood.
Acknowledgements
All illustrations by Dr Greta File. Property of KidsHealth.
