What is the antibiotic of choice for urinary tract infections (UTI) in pregnant women?

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Last updated: July 5, 2025View editorial policy

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From the Guidelines

Nitrofurantoin is the preferred antibiotic for treating urinary tract infections (UTI) in pregnant women, given its efficacy and safety profile, as indicated by the European Association of Urology guidelines 1. The choice of antibiotic for UTI in pregnant women is crucial due to the potential risks of untreated infections, including pyelonephritis, preterm labor, and low birth weight.

  • Key considerations in selecting an antibiotic include its effectiveness against common UTI pathogens, such as E. coli, and its safety during pregnancy.
  • According to the European Association of Urology guidelines 1, Nitrofurantoin macrocrystals can be prescribed at a dose of 50–100 mg four times a day for 5 days, or Nitrofurantoin monohydrate or macrocrystals at 100 mg twice daily for 5 days.
  • Alternative options, such as Cephalosporins (e.g., cefadroxil), may be considered based on local resistance patterns, but their use should be guided by susceptibility testing and pregnancy safety data.
  • Trimethoprim and trimethoprim-sulfamethoxazole have restrictions in pregnancy: trimethoprim should not be used in the first trimester, and trimethoprim-sulfamethoxazole should be avoided in the first and last trimesters due to potential fetal risks 1.
  • It is essential to obtain a urine culture before initiating antibiotic therapy and to consider a test of cure 1-2 weeks after completing treatment to ensure the infection has been adequately treated.

From the Research

Antibiotic Treatment for UTI in Pregnant Women

The choice of antibiotic for urinary tract infections (UTI) in pregnant women is crucial due to the potential risks to both the mother and the fetus.

  • First-line antibiotics recommended for the treatment of UTI in pregnant women include nitrofurantoin and fosfomycin trometamol 2.
  • Nitrofurantoin is commonly used for uncomplicated UTIs, while second-generation cephalosporins like cefuroxime may be used for both uncomplicated and complicated infections 3.
  • The American College of Obstetricians and Gynecologists (ACOG) recommends that sulfonamides and nitrofurantoin may be prescribed in the first trimester of pregnancy only when other antimicrobial therapies are deemed clinically inappropriate 4.
  • Other options for UTI treatment in pregnancy include amoxicillin and other cephalosporins, although they may have a higher chance of therapeutic failure 2.
  • For recurrent UTIs, all episodes should be confirmed by urine culture, and treatment should be initiated only after urine sampling with the same regimens indicated for isolated episodes 2.

Considerations for Antibiotic Resistance

  • The increasing resistance of bacteria to commonly used antibiotics is a concern in the treatment of UTIs in pregnant women 5.
  • Knowledge of local susceptibility patterns is essential in determining appropriate empiric antibiotic therapy for UTIs 5.
  • The use of new antimicrobials should be done wisely to avoid the development of resistance 5.

Screening and Prevention

  • Asymptomatic bacteriuria should be screened at least twice during pregnancy, and all cases of significant bacteriuria should be treated with antimicrobials considering safety and susceptibility profile 2.
  • Urine cultures should be collected in pregnant women, recurrent UTI, atypical cases, and if there is suspicion of pyelonephritis 2.
  • Prophylaxis options for recurrent UTI include behavioral measures, non-antimicrobial, and antimicrobial prophylaxis 2.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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