Pregnancy introduces a unique set of physiological changes to the urinary tract, and when a ureteral stent becomes necessary during this period, several considerations differ from stent placement in the general population. Hormonal effects and the growing uterus can both compress and dilate the ureters, and when a kidney stone or significant obstruction occurs, a ureteral stent may be used to maintain urine flow while protecting both maternal kidney function and pregnancy safety. This article looks at why stents are used in pregnancy and what makes their management distinct.
Why Does Pregnancy Sometimes Require Ureteral Stenting?
Pregnancy hydronephrosis — dilation of the kidney's collecting system — is commonly reported to some degree in a majority of pregnancies, largely due to hormonal relaxation of ureteral smooth muscle and mechanical compression from the enlarging uterus, more often affecting the right side. Most cases are mild and require no intervention. However, when hydronephrosis is accompanied by a obstructing stone, significant pain, infection, or worsening kidney function, a ureteral stent may be placed to bypass the blockage and allow urine to drain freely from the kidney to the bladder.
What Imaging Limits Apply During Pregnancy?
A key difference in managing urinary tract issues during pregnancy is the restriction on standard imaging tools. Computed tomography (CT), typically a first-line study for stone evaluation outside of pregnancy, is generally avoided due to ionizing radiation exposure to the fetus. Instead, ultrasound is the primary imaging modality, sometimes supplemented cautiously with magnetic resonance imaging (MRI) without contrast when more detail is needed. These imaging limits can make diagnosis less definitive than in non-pregnant patients, which is one reason clinicians may lean toward stent placement when hydronephrosis is symptomatic, rather than pursuing more invasive diagnostic steps.
How Often Are Stents Exchanged in Pregnant Patients?
Because pregnancy is associated with an increased tendency toward stent encrustation — related to changes in urine composition and prolonged dwell time — ureteral stents placed during pregnancy are often exchanged more frequently than the typical non-pregnant interval. Where a stent might otherwise remain in place for up to several months, many clinicians favor a shorter exchange schedule during pregnancy, sometimes every four to eight weeks, though the exact interval is set by the treating urologist based on individual risk factors. Regular exchange helps reduce the chance of stent blockage or infection as the pregnancy progresses.
The Role of Stent Material and Design in Pregnancy Cases
Stent composition and coating can influence comfort and encrustation risk over an indwelling period. INVAMED's UroFlow Ureteral Stents are manufactured from polyurethane (PUR), with an optional phosphorylcholine (PC) surface treatment intended to support long-term indwelling comfort and reduce encrustation tendency, as described by the manufacturer. Material selection is one factor among several — including exchange frequency and hydration — that clinicians weigh when managing a stent over an extended or pregnancy-adjusted timeline. More detail is available on the INVAMED UroFlow Ureteral Stents product page, and additional urology devices can be reviewed on the Urology & Incontinence Management category page.
What Happens After Delivery?
In most cases, once the pregnancy concludes and postpartum anatomical changes resolve, the underlying pressure on the ureters diminishes and the stent can be removed, provided the original obstructing issue (such as a stone) has also been addressed or has passed. A follow-up evaluation, sometimes including repeat imaging, helps confirm that the urinary tract has returned to its baseline state before the stent is discontinued.
Can stent-related discomfort be managed during pregnancy?
Stent-related symptoms such as urinary urgency, frequency, or flank discomfort are commonly reported and can sometimes be more noticeable during pregnancy due to bladder compression. A physician can discuss appropriate, pregnancy-safe symptom management strategies, and any severe pain or fever should prompt seeking immediate medical care.
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