What is the recommended treatment for pyelonephritis in pregnancy?

Treatment of Pyelonephritis in Pregnancy

For pregnant women with pyelonephritis, initial inpatient treatment with intravenous antibiotics is recommended, specifically using ceftriaxone 1-2g daily or cefepime 1-2g twice daily until afebrile for 48 hours, followed by oral antibiotics to complete 10-14 days of therapy. 1, 2

Diagnosis and Initial Assessment

• Pyelonephritis in pregnancy presents with fever (>38°C), chills, flank pain, nausea, vomiting, or costovertebral angle tenderness, with or without symptoms of cystitis 1
• Urinalysis (including assessment of white and red blood cells and nitrite) and urine culture with antimicrobial susceptibility testing should always be performed 1
• For imaging in pregnant women, ultrasound or MRI should be used preferentially to avoid radiation risk to the fetus 1
• Blood cultures should be obtained as bacteremia is reported in approximately 8-14% of pregnant women with pyelonephritis 3, 4

Treatment Approach

Initial Management

• Hospitalization is recommended for pregnant women with pyelonephritis, particularly in the second and third trimesters 5
• Initial intravenous hydration with normal saline is important 3
• Prompt differentiation between uncomplicated and potentially obstructive pyelonephritis is crucial, as the latter can rapidly progress to urosepsis 1

Antimicrobial Therapy

Inpatient Treatment

• Begin with intravenous antimicrobial therapy until the patient is afebrile for 48 hours 6, 7
• Recommended IV regimens include:
  • Ceftriaxone 1-2g once daily 1, 7
  • Cefepime 1-2g twice daily 1, 2
  • Cefazolin 1-2g every 6-8 hours 7, 4
  • Ampicillin plus gentamicin (alternative regimen) 4

Transition to Oral Therapy

• After clinical improvement (afebrile for 48 hours), transition to oral antibiotics to complete a total 10-14 day course 3, 6
• Oral options should be based on culture and susceptibility results 1
• Oral β-lactams (such as cephalexin) are appropriate options for completing therapy in pregnant women 3, 6

Duration of Therapy

• Complete a total of 10-14 days of antibiotic therapy 1
• The choice between agents should be based on local resistance patterns and optimized according to culture results 1

Special Considerations

• Fluoroquinolones (ciprofloxacin, levofloxacin) should be avoided during pregnancy due to potential fetal risks 1
• Trimethoprim-sulfamethoxazole should also be avoided, particularly in the first trimester (risk of neural tube defects) and near term (risk of neonatal hyperbilirubinemia) 1
• For patients with early culture results indicating multidrug-resistant organisms, consultation with infectious disease specialists may be needed for alternative regimens 1
• Some studies suggest outpatient treatment with intramuscular ceftriaxone may be safe in selected pregnant women with pyelonephritis before 24 weeks' gestation 6, 4

Follow-up

• Obtain a follow-up urine culture 5-14 days after completion of therapy to ensure clearance of infection 6, 4
• Monitor for recurrent infection throughout pregnancy, as approximately 6-8% of women may develop recurrent pyelonephritis 6, 4
• Surveillance for obstetric complications should continue until delivery 4

Pitfalls and Caveats

• Delayed treatment of pyelonephritis in pregnancy can lead to serious maternal and fetal complications, including preterm labor and sepsis 5
• Escherichia coli is the most common pathogen (75-95%), but local antimicrobial susceptibility patterns should guide empiric therapy 1
• Nitrofurantoin, oral fosfomycin, and pivmecillinam should be avoided for pyelonephritis as there are insufficient data regarding their efficacy 1
• Careful monitoring for clinical improvement is essential; consider changing antibiotics if the patient remains febrile after 72 hours of treatment 1