Hydronephrosis in babies and children – symptoms, causes & treatment in Malaysia

Hydronephrosis in babies is a condition which causes the enlargement of a kidney caused by excessive build-up of urine within it. It occurs when a blockage or reflux prevents urine from draining properly from the kidney to the bladder. One or both kidneys may be affected by hydronephrosis.
Hydro = water
Origin of the word Hydro-Nephrosis
Nephrosis = illness of the kidney
Hydronephrosis affects 1 in 100 children worldwide and in Malaysia.
Healthy kidneys help filter out wastes and fluid from the blood turning them into the urine, which may then flow out of the kidneys through tubes called ureters into the bladder. The tube that channels urine out of the bladder to the outside of the body is called the urethra.

An obstruction to the ureter prevents the normal passage of urine, causing a backup of urine to enlarge one or both kidneys.
The other cause of enlargement of the ureter with urine is due to urinary reflux or backflow from the bladder into the ureter or pelvis of the kidney.
Any form of distention of this part of the urinary tract with urine is known as Hydronephrosis.
For most children who are diagnosed with hydronephrosis on antenatal scans, the issue disappears by the time they are born or in early childhood. However, complications can arise, which is why early detection is essential.
It can be diagnosed before a baby is born (antenatally) or once they are born, (postnatally), and sometimes when they are older, in childhood.
What causes Hydronephrosis in babies?
Common causes of Hydronephrosis in babies are mostly birth defects:
- Bladder outlet obstruction in boys
- Obstruction at the Pelvic-ureteric junction (PUJ) or ureterovesical junction
- Kidney duplication (Duplex Kidney)
- Vesico- Ureteric Reflux disease
What are the symptoms of Hydronephrosis in babies?
If a baby is suffering from Hydronephrosis, he or she may display the following symptoms
- Unexplained fever
- discomfort when passing urine
- abdominal pain
- Lethargy and irritability
- Cloudy or Blood in the urine
A child with hydronephrosis may develop urinary tract infection. Symptoms of a urinary tract infection can include the following:
- Urge or frequent passage of urine
- Pain whilst urination
- cloudy urine
- back pain
- fever
- vomiting
Can Hydronephrosis be prevented?
Hydronephrosis in kids mostly happens during antenatal period so it cannot be prevented
However, there may be some ways to detect the emergence of this condition such as routine prenatal ultrasounds during pregnancy and regular physical examinations for infants after birth by a paediatrician.
What complications can arise if Hydronephrosis is left untreated?
If Hydronephrosis is left untreated it may lead to more advanced problems with the kidneys and other organs which include:
- Urinary tract infection
- Irreversible kidney damage
- Ureteric Stones
- Bladder dysfunction
How is Hydronephrosis in babies diagnosed?
Hydronephrosis in kids is now mostly diagnosed antenatally. In older kids, it can be diagnosed with a thorough medical history and physical examination. However, further diagnostic tests such as ultrasound may be necessary to confirm the diagnosis
An ultrasound shows whether there is any hold-up of urine within the urinary pipe between the kidney and bladder.

Hydronephrosis diagnosis may involve some additional tests to find out the cause of Hydronephrosis such as X-ray, intravenous pyelogram (IVP), computed tomography scan (CT), nuclear medical scans ( e.g. MAG3, DMSA, etc.), cystoscopy, ureteroscopy.

What is the treatment for Hydronephrosis in babies?
Hydronephrosis can be a serious condition as it may lead to kidney damage. The main role for any treatment is to preserve kidney function and avoid any further kidney damage. An obstructed kidney can lead to progressive and often non-reversible kidney damage as will an infection of the kidney.
Treatment for Hydronephrosis in babies may include:
ANTIBIOTICS for Vesico-ureteric reflux disease (VUR) and may require Deflux injection. The deflux injection for VUR does not involve any cuts and the procedure is done via a tiny scope inserted into the bladder. For the child patient, it is painless, like nothing was done to them. This procedure also has an amazingly high success rate.

SURGERY for Pelvi- Ureteric Junction (PUV) obstruction – treated with laparoscopic pyeloplasty (keyhole surgery). The laparoscopic procedure involves small incisions, and the children heal very well and are discharged 2 days after the surgery, almost pain-free.

What are the expected treatment outcomes for babies with Hydronephrosis?
Babies who have Hydronephrosis can usually be treated successfully through antibiotics or surgery early on before permanent damage to the kidneys occurs.
However, there are some cases where Hydronephrosis may have already resulted in long-term kidney damage or even kidney failure when they are diagnosed.
This is why early detection and treatment are critical.
Dr Nada featured in Easily SinChew on Hydroneprosis (22-0-2022)

Conclusion on Hydronephrosis
Hydronephrosis is a condition that affects the kidneys and can cause serious health complications if left untreated.
It is important to know the symptoms of Hydronephrosis in babies and to seek medical attention if you suspect your child has this condition.
Early detection and treatment are key to preventing any potential complications from arising.
If you have any questions or concerns about Hydronephrosis in babies, please do not hesitate to contact me for more information.
