Febrile UTI with Obstruction in a Pregnant Woman

Priority: sepsis from obstructed infected kidney. This is a urologic emergency - pyelonephritis with a likely obstructing stone in a pregnant patient. The combination of fever, tachycardia, hypotension, and rising creatinine suggests sepsis and possible obstructive uropathy.

Immediate steps:

1. Resuscitation: IV fluids (balanced crystalloid), blood cultures, urine culture, CBC, lactate, electrolytes, renal function.
2. Empiric IV antibiotics - cover gram-negatives; in pregnancy, cephalosporins (e.g., ceftriaxone) are safe. Avoid fluoroquinolones and aminoglycosides if alternatives exist (aminoglycosides are a risk to fetal eighth nerve). Adjust to culture.
3. Source control is the key step - antibiotics alone will not clear an obstructed infected system. Decompression is mandatory.

Imaging in pregnancy:

• Renal ultrasound first - safe, no radiation; assesses hydronephrosis. However, physiologic hydronephrosis of pregnancy (especially right side) can confound interpretation.
• If ultrasound is equivocal and obstruction is suspected, MR urography (without gadolinium) is preferred over CT. Low-dose CT is acceptable if it will change management and other modalities are unavailable - the risk of untreated sepsis outweighs radiation risk.
• Avoid gadolinium unless essential.

Source control options:

• Ureteral stent or percutaneous nephrostomy - both are acceptable. Stent placement under local anesthesia/light sedation; nephrostomy if stent fails or anatomy is difficult. Definitive stone treatment (ureteroscopy) can be deferred to postpartum unless the stone must be removed.
• Do not delay decompression for imaging perfection - if she is septic with a known stone and hydronephrosis, proceed.

Both achieve decompression; choice depends on patient and anatomy.

Ureteral stent:

• Pros: internal, no external tube, can be placed cystoscopically under local anesthesia, familiar to urologists.
• Cons: requires passage past the stone (may fail if stone is large/impacted or ureter is edematous), needs anesthesia/sedation, stent symptoms (irritation, urgency) are common and may be poorly tolerated in pregnancy, encrustation risk if left long-term, and can migrate.
• In pregnancy, stent placement is often successful but the physiologic ureteral dilation of pregnancy can both help and hinder.

Percutaneous nephrostomy (PCN):

• Pros: reliable decompression even when the stone cannot be bypassed; can be done under local anesthesia with ultrasound guidance; allows access for future stone treatment.
• Cons: external tube, risk of dislodgement, infection of the tube, requires radiology/interventional support, and patient must manage a drainage bag.

In this septic patient:

• If the stone is small and the ureter can be bypassed, stent is reasonable and avoids an external tube.
• If stent placement fails or the patient is unstable, PCN is the safer definitive decompression. Given sepsis and a known 8 mm stone (likely impacted), I would be prepared for PCN if stent fails.
• Either way, decompress urgently - do not wait for culture results.

Key trap: Assuming antibiotics alone suffice in an obstructed infected system - they do not. Also, do not defer decompression for definitive stone surgery; temporize.

Remainder of pregnancy:

• Complete the antibiotic course (often 7–14 days IV/oral based on culture), then suppressive antibiotics for the rest of pregnancy (e.g., cephalexin or nitrofurantoin - avoid nitrofurantoin at term due to hemolytic anemia risk in the neonate).
• Monitor the stent/PCN: stents in pregnancy encrust faster; plan exchange every 4–6 weeks if a stent is left in situ. PCN tubes need regular changes and site care.
• Repeat urine cultures monthly and treat asymptomatic bacteriuria (in pregnancy, treat even asymptomatic bacteriuria).
• Serial renal ultrasound to monitor hydronephrosis and stone position.
• Counsel on symptoms of recurrent infection or obstruction.

Definitive stone management:

• Defer definitive treatment to postpartum if the patient remains stable - ureteroscopy can be performed in pregnancy if necessary (second trimester is safest), but elective definitive treatment is generally postponed.
• Postpartum: Ureteroscopy with laser lithotripsy for the 8 mm stone; if it is a proximal stone, consider SWL or PCNL depending on anatomy and stone burden. An 8 mm stone is unlikely to pass spontaneously.
• Metabolic evaluation - she has recurrent UTIs and a stone; check calcium, uric acid, citrate, oxalate, and consider a stone analysis.
• Prevent recurrence: hydration, dietary counseling, and treat any anatomic predisposition.

Key trap: Leaving a stent in for the entire pregnancy without exchange - encrustation and infection risk. Also, forgetting suppressive antibiotics and monthly cultures.