II. Epidemiology

  1. Incidence: 2% of pregnancy
  2. Peak Incidence in the second and third trimesters

III. Pathophysiology

  1. Pregnancy factors that increase Pyelonephritis risk
    1. Increased GFR (results in Glycosuria, alkaluria)
    2. Increased Serum Progesterone (results in dilation of renal calyces, ureteral peristalsis stagnation)
    3. Bladder compression

IV. Symptoms

  1. Fever
  2. Chills
  3. Nausea
  4. Contractions
  5. Preterm Labor
  6. Acute Cystitis Symptoms

V. Signs

VI. Labs

  1. Urinalysis
  2. Urine Culture with Sensitivity
    1. Urinary Catheter sample not typically recommended
  3. Complete Blood Count
    1. Leukocytosis
  4. Blood Cultures
  5. Chemistry Panel (basic metabolic panel)
  6. Consider straining urine for calculi

VII. Imaging

VIII. Management: Inpatient

  1. Most pregnant patients with Pyelonephritis start with inpatient care
    1. Pregnant women have a higher risk of morbidity and mortality (Sepsis occurs in up to 17% of cases)
    2. Convert from IV to oral in first 48-72 hours
  2. Preferred Antibiotics: Patients at LOW risk for Bacterial resistance
    1. Ceftriaxone (Rocephin) 1 to 2 g IV q24 hours
      1. Avoid in the peripartum period due to risk of newborn Kernicterus
    2. Cefepime 2 g IV every 12 hours
    3. Unasyn 1.5-3g IV every 6 hours
      1. Other agents are preferred due to resistance rates
  3. Preferred Antibiotics: Patients at HIGH risk for multi-drug Bacterial resistance (or severe cases)
    1. Ertapenem 1 g IV every 24 hours
    2. Piperacillin-Tazobactam (Zosyn) 3.375 to 4.5 g IV every 6 hours
  4. Agents to AVOID
    1. Gentamicin had been historically used in combination with Ampicillin (no longer recommended)
      1. Ampicillin 2 g IV every 6 hours
      2. Gentamycin 1.5 mg/kg (Maximum 80-100 mg) q8 hours
        1. Adjust dosing per kinetics for >1-2 days use
  5. Other Inpatient Therapy
    1. Antipyretics and Analgesics
    2. Intravenous hydration
    3. When undergoing bedrest, lie in semi-Fowler's position
      1. Place on side opposite affected Kidney
  6. Transition to oral antibiotic timing
    1. Oral antibiotics when affebrile without CVA pain for 48 hours
    2. Complete a total of 7-14 days
    3. Consider Urinary Tract Infection prophylaxis

IX. Management: Outpatient antibiotics

  1. Typically follows inpatient initial antibiotics (see above)
  2. In uncommon stable pregnant patients, oral antibiotics may be started at outset
    1. Indications
      1. Tolerating oral antibiotics and oral fluids (with or without oral Antiemetics)
      2. No signs of Sepsis
      3. Compliant
      4. Close interval follow-up
    2. Give single dose of IV antibiotics while awaiting Urine Culture
      1. Ceftriaxone 1-2 g IV or
      2. Ertapenem (Invanz) 1 g IV
  3. Oral agents (higher resistance rates, accompany with initial dose of a broad spectrum IV antibiotic)
    1. Amoxicillin-Clavulanate (Augmentin) 875 mg orally twice daily for 14 days
    2. Cefixime (Suprax) 400 mg orally daily for 14 days
    3. Cefpodoxime 200 mg orally twice daily for 14 days
    4. Cephalexin (Keflex) 500 mg orally twice daily for 14 days
  4. Precautions
    1. Do NOT use Nitrofurantoin or fosfomycin
      1. Inadequate renal penetration to treat Pyelonephritis

X. Complications

  1. Sepsis (17% of Pyelonephritis cases in pregnancy)
  2. Acute Respiratory Distress Syndrome (in up to 8% of cases of Pyelonephritis in Pregnancy)
  3. Acute Kidney Injury
  4. Anemia
  5. Recurrent Pyelonephritis (6-8% of cases)
    1. Consider prophylaxis
    2. Nitrofurantoin 50-100 mg orally at bedtime until 6 weeks postpartum or
    3. Cephalexin (Keflex) 250-500 mg orally at bedtime until 6 weeks postpartum

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Related Studies

Ontology: pregnancy and pyelonephritis (C0747827)

Concepts Finding (T033)
ICD10 O23.0
English Pyelonephritis in pregnancy, pregnancy pyelonephritis, pregnancy and pyelonephritis, pyelonephritis pregnancy, pregnancy; pyelonephritis
Dutch zwangerschap; pyelonefritis