Hydronephrosis While Pregnant: Reasons, Signs & Remedies

Hydronephrosis During Pregnancy

Medically Reviewed By
Dr. Rima Sonpal (Gynecologist/Obstetrician)
View more Gynecologist/Obstetrician Our Panel of Experts

When it comes to pregnancy, you want to ensure that both you and the baby are in the best of health. Hydronephrosis is a condition that affects one or both the kidneys. Hydronephrosis can happen at any age and can affect pregnant women too. In fact, it is a common condition affecting pregnant women. Fear not, as there are ways to detect and manage this condition, making it essential to diagnose hydronephrosis in pregnancy as early as possible. If you are pregnant, this article gives you information on how it may affect your pregnancy and how you can deal with it.

What Is Hydronephrosis?

Hydronephrosis is a condition and not a disease. In hydronephrosis, one or both the kidneys swell as there is pressure on the kidneys and urine cannot drain from them. It is a structural or physiological condition that arises due to the way the uterus presses on the urinary bladder. As the bladder is unable to discharge its contents due to the pressure, the urine then travels back and causes the kidney to swell. It is accompanied by pain and can affect one or both kidneys.

Hydronephrosis in pregnant women is mostly observed in the second trimester, particularly between the 26th and 28th week of pregnancy. This condition in pregnancy often disappears on its own, typically within six weeks after the delivery. However, sometimes, the condition may persist for long and requires medical attention.

Hydronephrosis can cause pain in kidneys

What is Maternal/Gestational Hydronephrosis?

When hydronephrosis is caused due to the presence of a baby in the womb, it is called maternal or gestational hydronephrosis. It is caused due to conditions such as asymptomatic dilation of the renal calyces during pregnancy. There are other causes of hydronephrosis while pregnant, which you can read below.

Causes of Hydronephrosis During Pregnancy

There are several causes for the occurrence of hydronephrosis. Some of them are stated below –

  • One of the most common causes of hydronephrosis is a blockage in one or both the ureters. The ureter is a tube that connects the kidneys to the urinary bladder. The blockage could be due to kidney stones, scarring, or even blood clots.
  • Vesicoureteral reflux is another major cause of hydronephrosis in pregnancy. Vesicoureteral reflux (VUR) is the condition in which the muscular valve (where the urethra connects to the bladder) does not work properly. As a result, the urine flows backwards into the kidneys thus causing them to swell.
  • Tumours near or in the ureter can also cause hydronephrosis.
  • Narrow ureters due to some birth defect can even lead to hydronephrosis.
  • During pregnancy, the leading cause of hydronephrosis is the pressure of the uterus on the bladder and ureter.
  • Another cause of hydronephrosis during pregnancy is the increase in production of pregnancy hormones that relax the muscles.
  • Cancer of the urinary bladder and the cervix can also cause hydronephrosis.
  • Ovarian vein syndrome.
  • Diabetes.

Causes of Hydronephrosis

Signs and Symptoms of Hydronephrosis in Pregnant Women

There are not many symptoms of hydronephrosis but when this condition occurs you may notice the symptoms mentioned below. Remember that if you are pregnant, the chances of this condition manifesting will be very high. If you notice the following hydronephrosis during pregnancy symptoms, then you must seek immediate medical help.

How to Diagnose?

There are several methods health practitioners use to diagnose hydronephrosis. These methods will help her understand and identify if something is wrong with your urinary system.

  • An ultrasound is one of the most reliable methods of diagnosing hydronephrosis, especially if the cause is physiological. A variety of causes for the condition can be determined using this method including kidney stones and other obstructions.

  • Urine analysis is also suggested to determine if there is an infection in the urinary system.

  • Your doctor might recommend a blood test to check for anaemia as it is one of the most common conditions in pregnant women.

  • GFR and electrolyte analysis to check the proper functioning of the kidneys can also be done.

Diagnosis of Hydronephrosis

Risks of Hydronephrosis

There are some risks associated with hydronephrosis that you must be aware of. If there is undue pressure on your kidneys, a spontaneous renal rupture can take place. If your kidneys were damaged previously, then the chances of a spontaneous renal rupture will be much higher.

This condition should not be left untreated as it could cause the kidneys to stop working completely. Be sure to get regular check-ups to monitor the health of your kidneys and the urinary system. Your doctor can develop a treatment plan that will ease the pressure on your kidneys.

Treatment for Hydronephrosis During Pregnancy

The management of hydronephrosis in pregnancy is done carefully through different stages.

  • The first step of treatment in case of hydronephrosis is using a catheter to drain the urine from the bladder to ease the pressure off the kidneys.

  • The next step in treatment involves figuring out the cause of the obstruction. Different causes will have different treatments. For instance, the treatment for kidney stones will be different from the treatment for scarring on the ureter.

  • Pregnancy-related hydronephrosis can be treated using analgesics and antibiotics or through pigtail insertion.

Prevention of Hydronephrosis

Unfortunately, most renal disorders do not have symptoms. When it comes to avoiding severe hydronephrosis during pregnancy all you can do is go for regular check-ups. Be sure to get your kidneys scanned regularly along with urine and blood tests to scan for infections.

Visit doctors regularly

Discuss your concerns with your doctor and give her a full history of your medical health particularly if you have had previous renal disorders. You must check-in regularly with her and she will keep a lookout for any warnings of renal disorders particularly that of mild hydronephrosis.

When To Call the Doctor?

If you notice symptoms of hydronephrosis during pregnancy, such as vomiting accompanied by swelling in the legs, fever, or blood in urine, it is best to immediately contact a doctor. A healthcare provider can conduct the right tests to diagnose any underlying conditions.


1. On Which Side Does Hydronephrosis in Pregnancy Usually Occur On?

Hydronephrosis during pregnancy usually occurs on the right side more often that the left side, due to reasons such as shifting of the baby in the womb, and more.

2. How Does Hydronephrosis Affect the Baby?

In severe cases, hydronephrosis during pregnancy can cause urine to be collected in the urinary tract, which leads to low levels of amniotic fluid in the womb. This can be harmful to the baby. Hence, it is best to consult a doctor if you notice the symptoms.

Hydronephrosis can be a painful experience during pregnancy due to the undue pressure on the kidneys. Its symptoms can cause a lot of discomfort. Remember that most women suffer from this condition during pregnancy and you must keep an eye out for the symptoms mentioned above. You must seek immediate help if you experience fever, blood in the urine, and acute pain in the abdomen or back.


1. Rasmussen. P, Nielsen. F; Hydronephrosis during pregnancy: a literature survey; PubMed; https://pubmed.ncbi.nlm.nih.gov/3280355/

2. Hydronephrosis; NHS; https://www.nhs.uk/conditions/hydronephrosis/; December 2021

3. Hydronephrosis; Cleveland Clinic; https://my.clevelandclinic.org/health/diseases/15417-hydronephrosis; May 2019

4. El-Feky. M; Maternal hydronephrosis in pregnancy; Radiopaedia; https://radiopaedia.org/articles/maternal-hydronephrosis-in-pregnancy?lang=us; July 2023

5. Ciciu. E, Pastau-Cornea. A, Petcu. L, et al.; Early diagnosis and management of maternal ureterohydronephrosis during pregnancy; PubMed Central; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8611492/; January 2022

Also Read:

Uterus Abnormalities during Pregnancy
Epithelial Cells in Urine while Pregnant
Kidney Infection (Pyelonephritis) when Pregnant?

Previous article «
Next article »