Hydronephrosis In Infants - Reasons, Signs & Treatment

Hydronephrosis in Babies: Causes, Symptoms & Treatment

Medically Reviewed By
Dr. Gunjan Baweja (Paediatrician)
View more Paediatrician Our Panel of Experts

Hydronephrosis can be an extremely painful condition of the renal system, and can affect anyone, including babies. If your baby seems irritable, or cries when urinating, it is best that you consult your paediatrician. This condition should not be ignored, as it can have harmful effects. Let’s take an in-depth look into hydronephrosis.

What Is Hydronephrosis?

Hydronephrosis is a medical condition of the renal system wherein urine cannot be discharged, thus causing pain while urinating. The urine moves back towards the kidneys and causes swelling and pressure on the kidney tissue. The blockage is usually located in the ureter. Ureters are the tubes connecting the kidney to the bladder. In babies, it is caused mostly by a congenital disease (a disease present from birth) of the renal system. The disease can affect one or both kidneys. The latter is known as bilateral hydronephrosis in infants.

What Is Hydronephrosis?

Causes of Baby Hydronephrosis

There are many reasons why your child could be suffering from this ailment, apart from it being congenital hydronephrosis. These can be any of the following:

  • One of the main causes of hydronephrosis is the presence of kidney stones. If the stones are too large, it might lead to blocking of the ureter, resulting in collection of the urine that will eventually cause swelling in the kidneys.
  • Hydronephrosis can be caused by the presence of a tumour or cyst, which presses against the ureter, causing a blockage.
  • Another leading cause is the presence of blood clots or scar tissue. Scarring is generally not observed in babies unless they have had some renal damage before.
  • Some babies are naturally born with narrow ureters. In such cases, the ureter is more susceptible to blockages.

Symptoms of Hydronephrosis in Babies

There are many symptoms of this condition for which you can look out. Some of these symptoms include:

  • Crying during urination, which can be indicative of pain
  • Pain in the lower abdomen, which can be observed if your baby cries when you gently palpate or press on the region
  • Urination that is more frequent than usual
  • Nausea in older children
  • Vomiting
  • Fever

Keep in mind that the longer this condition remains untreated, the worse the symptoms will appear to be. So, look out for these signs, and if you notice any, get in touch with your paediatrician for treatment as soon as possible.

One of the most common side effects of hydronephrosis is the development of urinary tract infections or UTIs. Some common symptoms of this infection are:

  • Back pain
  • Fever
  • Cloudy urine
  • Pain when urinating indicated via crying or irritability

Symptoms of Hydronephrosis in Babies


Since hydronephrosis is not a disease in itself, but rather a condition caused by other factors, the diagnosis is two-pronged. The first step would be to establish that the condition exists in your baby. The second step would be to determine what is causing the blockage.

The diagnosis of the condition can be done during your pregnancy, or after.

Prenatal Testing

During your pregnancy, hydronephrosis is usually diagnosed through your regular prenatal ultrasound checkup. If the size of your child’s kidneys as well as the level of amniotic fluid seem to suggest that something could be wrong, then your doctor will have you come in for more checkups to monitor the health of your baby’s kidneys.

Postnatal Testing

Doctors have advanced tools and tests at their disposal, which can accurately diagnose issues plaguing your baby’s kidneys. They might recommend one, multiple, or all the tests below to identify the issue:

  • Renal Ultrasound (RUS): This ultrasound is focused directly over the renal system of your baby, to give the doctor a better and complete picture of the condition of the kidneys.
  • Voiding Cystourethrogram (VCUG): In this test, a liquid dye is injected into your baby’s bladder using a catheter. Once your baby urinates, the flow of the dye will be picked up via an X-ray.
  • Renal Scan (MAG 3): This test involves injecting a small amount of radioisotope into your baby’s bloodstream. As it finds its way into the renal system, a special gamma camera will take pictures of the radioisotope. With this test, the doctor will be able to compare the functioning of both the kidneys, while also determining the extent of the blockage.


If hydronephrosis is left untreated or is given improper medical care, your baby’s kidneys could get severely damaged. Apart from the kidneys stopping their regular function of filtering the blood, removing toxins, waste excretion, RBC regulation, and regular urination, they could also get infected or permanently damaged.

There are cases where the baby continues to suffer from hydronephrosis, and the prognosis is bleak even after timely medical intervention.

Treatment of Hydronephrosis in Infants

The nature and method of the treatment will depend on the stage or type of hydronephrosis in your baby. Some of the options for treatment are:

  • Foetal intervention: If the condition of the kidneys and the rest of the renal system looks to be critical, then your doctor will want to intervene at that time itself. This will include neonatal surgery and maternal-foetal medicine.
  • Observation: In cases of a mild to moderate condition of hydronephrosis, the paediatrician will recommend that the best line of treatment would be to simply observe the renal system as it corrects itself. Your baby might, at most, get a low dosage of antibiotics, which will prevent any infection of the urinary tract.
  • Surgery: Your doctor will recommend surgery to correct hydronephrosis only in the most severe cases. There are a number of surgeries that could be done, such as kidney stone removal if kidney stones are causing the blockage. One of the most common surgeries is pyeloplasty, wherein the portion of the ureter with the blockage is removed.

Hydronephrosis is a condition of the renal system that can cause serious complications, apart from just causing pain. In order to avoid critical and severe cases of hydropnephrosis, it is advisable that you immediately seek the advice of your paediatrician as soon as you spot the first few signs. Keep in mind that most cases of congenital hydronephrosis can get resolved on its own, and there is no need to rush to surgery unless recommended by the doctor. Make sure you get all the required tests done on time, and be diligent in keeping appointments with the paediatrician.

Also Read: Cerebral Palsy in Babies

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