What is the recommended treatment for a Urinary Tract Infection (UTI) in a pregnant patient at 32 weeks and 4 days gestation?

Treatment of UTI in Pregnancy at 32 Weeks and 4 Days

For a pregnant patient at 32 weeks and 4 days gestation with a urinary tract infection, nitrofurantoin 50-100mg four times daily for 5-7 days is the recommended first-line treatment, as it is considered safe and effective during pregnancy with minimal transfer into breast milk. 1

First-Line Treatment Options

• Nitrofurantoin 50-100mg QID for 5-7 days

  • Safe during pregnancy 1, 2
  • Minimal transfer into breast milk 1
  • Low resistance rates 1

• Fosfomycin 3g single dose

  • Comparable efficacy to nitrofurantoin 1
  • Single-dose administration reduces exposure 1
  • Safe option during pregnancy 2

• Amoxicillin-clavulanate 500mg TID for 3-7 days

  • Beta-lactams are generally considered safe in pregnancy 2
  • Consider local resistance patterns before prescribing 1

Important Considerations

Diagnostic Confirmation

• Obtain urinalysis and urine culture before initiating treatment 1
• Document positive urine cultures for future reference 1

Treatment Duration

• 5-7 days is recommended for uncomplicated cystitis 1, 3
• For pyelonephritis, 7-14 days of treatment is needed 1
• Hospitalization and IV antibiotics are indicated for pyelonephritis in pregnancy 3

Follow-Up

• Obtain a repeat urine culture 1-2 weeks after treatment to confirm eradication 1
• Monitor for symptoms of recurrence or progression to pyelonephritis

Medications to Avoid

• Fluoroquinolones - generally avoided in pregnancy 1, 2
• Tetracyclines - contraindicated in pregnancy 2
• Trimethoprim-sulfamethoxazole - avoid in third trimester due to risk of kernicterus 2

Clinical Pearls

• UTIs in pregnancy are associated with significant morbidity, including preterm birth, low birth weight, and spontaneous abortion if left untreated 2
• Physiologic changes in pregnancy (increased GFR, increased total body volume, enhanced cardiac output) may alter antibiotic pharmacokinetics 2
• Asymptomatic bacteriuria should also be treated in pregnancy to prevent progression to pyelonephritis 1
• E. coli remains the most common pathogen in UTIs 3

Common Pitfalls to Avoid

1. Failing to obtain a urine culture before initiating treatment
2. Using antibiotics with poor tissue penetration for suspected pyelonephritis
3. Not confirming cure with a follow-up urine culture
4. Prescribing fluoroquinolones or tetracyclines, which should be avoided in pregnancy
5. Inadequate treatment duration, which may lead to recurrence or progression to pyelonephritis

By following these evidence-based recommendations, UTIs in pregnancy can be effectively managed while minimizing risks to both mother and fetus.