Treatment of Urinary Tract Infections During Pregnancy
For urinary tract infections during pregnancy, first-line treatments include nitrofurantoin (5-day course), fosfomycin trometamol (single 3g dose), or cephalosporins (3-5 day course), with treatment selection based on local resistance patterns and trimester of pregnancy. 1
Diagnosis and Screening
- A urine culture is specifically recommended for pregnant women with suspected UTI to confirm diagnosis and guide appropriate treatment 2, 1
- Pregnant women should be screened for bacteriuria by urine culture at least once in early pregnancy, even if asymptomatic 2
- Screening for pyuria alone has low sensitivity (approximately 50%) for identifying bacteriuria in pregnant women 2
First-Line Treatment Options
- Nitrofurantoin (100 mg twice daily for 5 days) is effective and safe during pregnancy except in the last trimester 2, 1
- Fosfomycin trometamol (single 3g dose) offers convenient administration and comparable efficacy to multi-day regimens 1, 3
- Cephalosporins (e.g., cefadroxil 500 mg twice daily for 3 days) are appropriate when local E. coli resistance is <20% 2
- Treatment duration is typically 5-7 days for symptomatic UTIs in pregnancy, with shorter courses generally not recommended 1
Medication Restrictions and Precautions
- Trimethoprim should not be used in the first trimester of pregnancy due to potential teratogenic effects 2
- Trimethoprim-sulfamethoxazole should be avoided in the last trimester due to risk of neonatal hyperbilirubinemia 2
- Fluoroquinolones are contraindicated during pregnancy 1
- Nitrofurantoin should be avoided near term (last trimester) due to risk of hemolytic anemia in the newborn 1
Follow-up and Recurrent UTIs
- For women whose symptoms don't resolve by the end of treatment or recur within 2 weeks, urine culture and antimicrobial susceptibility testing should be performed 2
- Retreatment with a 7-day regimen using a different agent should be considered for persistent or recurrent infections 2
- For pregnant women with history of recurrent UTIs, postcoital prophylaxis with a single dose of cephalexin (250 mg) or nitrofurantoin (50 mg) has shown significant effectiveness in preventing recurrences 4
Treatment Efficacy
- Studies comparing different antibiotic regimens for UTI in pregnancy have found similar cure rates among most agents 5, 6
- Meta-analysis shows no significant differences in clinical cure rates (RR 0.95% CI 0.81-1.12) or microbiological cure rates (RR 0.96,95% CI 0.84-1.08) between fosfomycin and nitrofurantoin 3
- Treating asymptomatic bacteriuria in pregnancy significantly reduces the risk of pyelonephritis from approximately 20-30% to 1-4% 2
Common Pitfalls to Avoid
- Failing to obtain a urine culture before initiating treatment in pregnant women 2, 1
- Using antibiotics that don't achieve adequate urinary concentrations 1
- Not following up with repeat urine culture after treatment to ensure resolution 2
- Using fluoroquinolones or trimethoprim in contraindicated trimesters 2, 1
- Treating asymptomatic bacteriuria outside of pregnancy (not recommended in most non-pregnant populations) 1