Pregnancy-Related Hydronephrosis: Understanding Catheterization, Discomfort, and Treatment Options

Hydronephrosis, or the swelling of a kidney due to urine buildup, is a relatively common condition during pregnancy. As the uterus expands throughout gestation, it can exert pressure on the ureters—tubes that carry urine from the kidneys to the bladder—or interfere with normal bladder emptying. This compression may lead to urinary obstruction and subsequent kidney swelling. While the idea of catheter insertion might sound alarming, most pregnant women report minimal discomfort during the procedure. In fact, many describe only a mild sensation rather than actual pain.

How Is Hydronephrosis Assessed During Pregnancy?

The severity of hydronephrosis is typically evaluated using ultrasound imaging, focusing on the degree of renal pelvic dilation. Medical professionals use specific measurements to determine the extent of the condition:

Mild Hydronephrosis (4–9 mm)

When the renal pelvis measures between 4 and 9 millimeters, it's classified as mild hydronephrosis. In most cases, no immediate intervention is required. Doctors usually recommend regular monitoring through follow-up ultrasounds to ensure the condition doesn't progress.

Moderate Hydronephrosis (9–14 mm)

A measurement in this range indicates moderate kidney swelling. While not an emergency, closer observation is advised. Physicians may suggest lifestyle adjustments, increased hydration, and positional changes to help improve urinary flow and reduce pressure on the urinary tract.

Severe Hydronephrosis (>14 mm)

When dilation exceeds 14 mm, it's considered severe. Prolonged obstruction at this level can impair kidney function and increase the risk of infection, such as pyelonephritis. In these cases, medical intervention becomes necessary to protect both maternal and fetal health.

Types of Catheterization and Associated Discomfort

Urinary Catheterization: If poor bladder emptying is the primary cause, a standard urinary catheter may be inserted through the urethra to drain the bladder. Most patients experience only slight discomfort during placement, especially when a lubricated catheter is used. Local anesthetics can further minimize any sensation.

Percutaneous Nephrostomy: In more complex cases where the ureter is significantly compressed, a nephrostomy tube may be placed directly into the kidney through the skin under imaging guidance. While this procedure involves more steps and can cause mild to moderate discomfort, it is performed under local anesthesia or sedation, making the experience tolerable for most patients.

What to Expect After Catheter Placement?

Once the catheter is in place, many women report relief from symptoms such as flank pain, pressure, or frequent urination. The device is generally well-tolerated, and patients can continue their daily activities with minor adjustments. Regular follow-ups ensure proper function and timely removal when no longer needed.

It's important to note that while hydronephrosis during pregnancy is often physiological and resolves after delivery, timely assessment and treatment are crucial when complications arise. Open communication with your healthcare provider ensures personalized care and optimal outcomes for both mother and baby.