What is the recommended treatment for urinary tract infections (UTIs) in pregnancy?

Treatment of UTIs in Pregnancy

For pregnant women with urinary tract infections, first-line treatment should be nitrofurantoin (100 mg twice daily for 5 days), fosfomycin trometamol (3 g single dose), or cephalosporins (such as cefixime) for 5-7 days, with nitrofurantoin avoided near term and trimethoprim-sulfamethoxazole avoided in the first and third trimesters. 1

Diagnostic Approach

• Always obtain a urine culture in pregnant women with UTI symptoms before initiating treatment to confirm diagnosis and guide antibiotic selection 1
• Pregnancy is classified as a "complicated UTI" scenario, requiring more careful antibiotic selection and longer treatment courses than non-pregnant women 2

First-Line Antibiotic Options

Nitrofurantoin

• Nitrofurantoin 100 mg twice daily for 5 days is safe and effective throughout most of pregnancy 1
• Critical caveat: Avoid nitrofurantoin in the last trimester due to risk of hemolytic anemia in the newborn 1
• Demonstrates low resistance rates and is preferred for re-treatment when needed 2

Fosfomycin Trometamol

• Single 3 g oral dose provides excellent compliance and equivalent efficacy to multi-day regimens 1, 3
• Particularly useful when patient compliance with multi-day regimens is a concern 1
• Meta-analysis shows no significant difference in clinical cure rates compared to nitrofurantoin (RR 0.95% CI 0.81-1.12) 3

Cephalosporins

• Cefixime and other third-generation cephalosporins are appropriate alternatives, especially when resistance to other agents is suspected 1, 4
• Cephalosporins demonstrate high sensitivity against E. coli, the primary uropathogen 4

Treatment Duration

• Standard treatment duration is 5-7 days for symptomatic UTIs in pregnancy 1
• Shorter courses (1-3 days) are not recommended for pregnant women, unlike non-pregnant populations 1
• Single-dose fosfomycin is the exception to this rule 1, 5

Critical Medications to Avoid

Trimethoprim-Sulfamethoxazole

• Contraindicated in the first trimester due to potential teratogenic effects including neural tube defects 2, 1
• Contraindicated in the third trimester due to risk of neonatal hyperbilirubinemia and kernicterus 2, 1
• Despite being commonly prescribed, it carries significant risks at both ends of pregnancy 6

Fluoroquinolones

• Absolutely contraindicated throughout pregnancy due to effects on fetal cartilage development 1
• Despite this, ciprofloxacin remains one of the most frequently prescribed antibiotics for UTIs in pregnant women, representing a significant prescribing error 6

Special Considerations

Asymptomatic Bacteriuria in Pregnancy

• Screen for and treat asymptomatic bacteriuria in pregnant women with standard short-course treatment or single-dose fosfomycin 2
• This differs from non-pregnant populations where asymptomatic bacteriuria should not be treated 2, 1
• Untreated bacteriuria in pregnancy carries risks of pyelonephritis, preterm labor, low birth weight, and sepsis 6

Recurrent UTIs in Pregnancy

• Daily low-dose antibiotic prophylaxis can be used for pregnant women with frequent recurrences 1
• Post-coital prophylaxis with cephalexin 250 mg or nitrofurantoin 50 mg as a single dose is highly effective, reducing UTI incidence from multiple episodes to near zero during pregnancy 7
• Rotating antibiotics at 3-month intervals may be considered to prevent antimicrobial resistance development 2

Common Pitfalls to Avoid

• Do not use antibiotics that fail to achieve adequate urinary concentrations, such as certain macrolides 1
• Avoid classifying all pregnant women with UTIs as requiring broad-spectrum antibiotics; reserve these for true complicated infections with structural abnormalities or immunosuppression 2
• Do not treat persistent symptoms without repeat urine culture to assess for ongoing bacteriuria before prescribing additional antibiotics 2
• Avoid prolonged antibiotic courses (>7 days) unless treating pyelonephritis, as this fosters antimicrobial resistance 2

Antibiotic Selection Algorithm

When choosing empiric therapy:

• Consider prior culture data if available to guide initial selection 2
• Review local antibiogram patterns for community resistance rates 2
• Account for trimester-specific contraindications: avoid trimethoprim-sulfamethoxazole in first and third trimesters, avoid nitrofurantoin near term 2, 1
• Assess patient allergies and prior adverse reactions 2
• Prioritize narrow-spectrum agents (nitrofurantoin, fosfomycin) over broad-spectrum options (fluoroquinolones, cephalosporins) when susceptibility allows 2

Follow-Up

• Repeat urine culture 7 days after completing therapy to document cure 8
• If symptoms persist despite treatment, obtain repeat culture before prescribing additional antibiotics to avoid treating resistant organisms with ineffective agents 2