Impact of Hydronephrosis During Pregnancy: Causes, Risks, and Management
Hydronephrosis during pregnancy can raise concerns for both maternal and fetal health, but its effects largely depend on the underlying cause. While some cases are a normal part of pregnancy, others may require careful monitoring or postpartum intervention. Understanding the different types and their implications is essential for ensuring a safe and healthy pregnancy journey.
Physiological Hydronephrosis: A Common and Natural Occurrence
During pregnancy, it's not uncommon for women to experience mild to moderate hydronephrosis due to natural anatomical changes. As the uterus expands in the second and third trimesters, it often compresses the lower portion of the ureters—particularly on the right side—slowing urine flow from the kidneys to the bladder. This physiological condition affects up to 80% of pregnant women and is considered a normal adaptation rather than a disease.
The good news is that this type of kidney swelling typically resolves on its own after delivery. It rarely causes long-term damage to kidney function and usually doesn't require medical treatment. Routine prenatal ultrasounds often detect this condition, allowing healthcare providers to monitor it without alarm.
Hydronephrosis Caused by Kidney Stones: Challenges in Treatment
When hydronephrosis results from ureteral stones, the situation becomes more complex, especially during pregnancy. Managing kidney stones in expectant mothers requires a delicate balance between relieving maternal pain and protecting fetal well-being. Many standard treatments—such as certain medications, extracorporeal shock wave lithotripsy (ESWL), or invasive surgical procedures—are generally avoided due to potential risks to the developing baby.
In most cases, doctors recommend conservative management, especially during the first and second trimesters. This includes increasing fluid intake, staying physically active with light walking, and using safe pain relief methods under medical supervision. The goal is to encourage the natural passage of the stone through increased urine flow. If symptoms persist or infection develops, minimally invasive options like ureteral stenting or nephrostomy tube placement may be considered in the later stages of pregnancy.
Risks Associated With Untreated Stones
Left unmanaged, kidney stones can lead to complications such as urinary tract infections (UTIs), sepsis, or impaired kidney function—all of which pose risks to both mother and fetus. Therefore, close follow-up with an obstetrician and urologist is crucial when hydronephrosis is linked to calculi.
Congenital Ureteral Narrowing: A Condition Often Diagnosed Late
Some women discover they have congenital abnormalities like ureteropelvic junction (UPJ) obstruction only during pregnancy, when routine imaging reveals unexpected kidney dilation. These structural issues may have gone unnoticed before because they didn't cause noticeable symptoms in daily life.
Pregnancy acts as a "stress test" for the urinary system, often unmasking pre-existing conditions due to increased blood flow and hormonal changes that affect kidney function. In such cases, while the hydronephrosis may worsen during gestation, definitive surgical correction—such as pyeloplasty—is typically postponed until after childbirth.
Postpartum Care and Long-Term Outlook
After delivery, patients diagnosed with congenital narrowing should undergo a full urological evaluation. Imaging tests like CT urography or diuretic renography help determine the extent of blockage and guide treatment decisions. With proper intervention, most women achieve excellent outcomes and preserve long-term kidney health.
In summary, while hydronephrosis in pregnancy can stem from various causes—from normal physiological changes to more serious structural or obstructive issues—most cases are manageable with appropriate care. Early detection, multidisciplinary coordination between OB-GYNs and urologists, and informed decision-making play key roles in safeguarding both maternal and fetal health throughout pregnancy and beyond.