What antibiotic is recommended to treat urinary tract infection (UTI) in pregnancy?

Antibiotic Treatment for UTI in Pregnancy

For pregnant women with UTI, nitrofurantoin is the first-line treatment option due to its proven safety and efficacy in pregnancy, with a recommended dosage of 100 mg twice daily for 5 days. 1

First-Line Treatment Options for UTI in Pregnancy

• Nitrofurantoin: 100 mg twice daily for 5 days

  • Safe in pregnancy except in the third trimester (near term) due to risk of hemolytic anemia in the newborn
  • High efficacy against common uropathogens including E. coli
  • Low resistance rates compared to other antibiotics 1, 2

• Fosfomycin trometamol: 3 g single dose

  • Convenient single-dose regimen
  • Effective against most uropathogens
  • Limited clinical evaluation in pregnancy but considered safe 3, 1, 4

• Beta-lactams (such as amoxicillin-clavulanate):

  • Effective for UTIs caused by beta-lactamase-producing E. coli and Klebsiella species 5
  • Typically used for 7 days 1
  • Good safety profile in pregnancy

Treatment Considerations

Duration of Treatment

• For uncomplicated cystitis: 5-7 days depending on the antibiotic
• For pyelonephritis: 7-14 days, often starting with IV antibiotics 1
• Single-dose regimens (except fosfomycin) are less effective than multi-day courses in pregnancy 3

Antibiotic Selection Factors

1. Safety in pregnancy: Avoid trimethoprim-sulfamethoxazole in first and third trimesters due to risk of neural tube defects and kernicterus, respectively 1
2. Local resistance patterns: Consider community-specific antibiotic resistance data
3. Severity of infection: Pyelonephritis requires more aggressive treatment, often starting with parenteral therapy
4. Patient allergies and medication history

Special Considerations

• Asymptomatic bacteriuria: Should be treated in pregnancy (unlike in non-pregnant patients) as it increases risk of pyelonephritis and adverse pregnancy outcomes 3
• Pyelonephritis: Requires hospitalization and IV antibiotics initially (ceftriaxone, cefotaxime, or ampicillin plus aminoglycoside), with transition to oral therapy once clinically improved 1
• Recurrent UTIs in pregnancy: May require prophylactic antibiotics after treatment of the acute infection 3

Follow-up

• Obtain urine culture 1-2 weeks after completing treatment to confirm cure
• Screen for recurrent or persistent bacteriuria throughout pregnancy
• Avoid unnecessary urine testing in asymptomatic patients after documented cure 3

Prevention Strategies

• Increase fluid intake
• Urinate before and after sexual activity
• Proper wiping technique (front to back)
• Avoid irritating feminine products 1

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