What is the best next step in managing a 24-year-old primigravida (first pregnancy) at 26 weeks gestation with symptoms of urinary frequency, back pain, and a history of nephrolithiasis (kidney stones), presenting with normal fetal movement, mild hypertension, and impaired renal function, as evidenced by bilateral renal enlargement and dilation of the renal pelvis and proximal ureter on ultrasound?

From the Guidelines

The best next step in management for this 24-year-old pregnant woman with urinary frequency and back pain is conservative treatment with increased fluid intake, regular voiding, and acetaminophen for pain relief. Her symptoms are consistent with physiologic hydronephrosis of pregnancy, a common condition occurring in 80-90% of pregnant women, especially in the second and third trimesters. The ultrasound findings of bilateral kidney enlargement with dilation of the renal pelvis and proximal ureters confirm this diagnosis. This condition occurs due to mechanical compression of the ureters by the enlarging uterus, particularly on the right side (as seen in this patient), and hormonal effects of progesterone causing ureteral relaxation. Her history of nephrolithiasis is relevant but her current presentation lacks signs of infection (normal temperature, negative leukocyte esterase) or obstruction (normal creatinine) 1. If conservative management fails to provide relief, positioning interventions like sleeping on her left side may help reduce pressure on the right ureter. Close monitoring should continue, and if symptoms worsen or signs of infection or obstruction develop, further intervention such as ureteral stent placement might be necessary, as suggested by the American Urological Association guideline 1. However, at this stage, conservative management is appropriate as physiologic hydronephrosis typically resolves spontaneously after delivery. It's also important to note that ureteral stent and nephrostomy tube are alternative options, with frequent stent or tube changes usually being necessary, and URS provides a definitive treatment for the pregnant patient, as it accomplishes stone clearance, obviating the need for prolonged drainage with stent or percutaneous nephrostomy 1. Key points to consider in management include:

• Conservative treatment as first-line therapy for patients with well-controlled symptoms 1
• Close monitoring for recurrent or persistent symptoms
• Consideration of ureteral stent placement or URS if symptoms worsen or signs of infection or obstruction develop
• Awareness of the potential need for frequent stent or tube exchanges due to encrustation 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Patient Presentation and History

• The patient is a 24-year-old woman, gravida 1 para 0, at 26 weeks gestation, presenting with increased urinary frequency and back pain.
• She has a history of recurrent nephrolithiasis outside of pregnancy.
• Laboratory results and renal and pelvic ultrasound reveal bilateral enlargement of the kidneys, dilation of the renal pelvis and proximal ureter on both sides.

Management Options

• The patient's condition requires an intervention such as ureteral stent or percutaneous nephrostomy tube (PCNT) placement, especially in the setting of urinary tract infection (UTI) 2.
• Studies have compared the use of percutaneous nephrostomy and ureteral stenting in the management of ureteral obstruction, with no consensus on the ideal treatment or treatment pathway 3.
• A retrospective cohort study compared percutaneous nephrostomy and ureteral DJ stent in patients with obstructive pyelonephritis, finding both methods to be effective and safe, despite higher complication rates in the DJ stent group 4.

Pregnancy Considerations

• A propensity score-matched analysis of a large multi-institutional research network found no significant difference in rates of adverse pregnancy events between ureteral stents and percutaneous nephrostomy tubes in the treatment of nephrolithiasis during pregnancy 5.
• However, ureteral stent placement was associated with a lower incidence of hospital admissions, emergency department visits, exchange procedures, and new UTIs or pyelonephritis 5.
• A prospective evaluation of antibiotic management in ureteral stent and nephrostomy interventions found that peri-interventional antibiotic treatment may be omitted in patients without symptomatic UTI 6.

Next Steps

• Considering the patient's symptoms and history, the best next step in management would be to consider ureteral stent placement, given its association with lower incidence of hospital admissions, emergency department visits, exchange procedures, and new UTIs or pyelonephritis 5.
• However, the decision should be made on a case-by-case basis, taking into account the patient's individual needs and medical history, as well as the potential risks and benefits of each intervention 2, 3, 4, 5, 6.