What is the recommended treatment for Urinary Tract Infection (UTI) during the second trimester of pregnancy?

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From the Guidelines

For UTI treatment during the second trimester of pregnancy, the recommended first-line treatment is Nitrofurantoin macrocrystals (50–100 mg q.i.d. for 5 days) or Nitrofurantoin monohydrate/macrocrystals (100 mg b.i.d. for 5 days) 1.

Treatment Approach

The choice of antibiotic should be based on the patient's allergy history, tolerance, and local resistance patterns.

  • Nitrofurantoin is a commonly used antibiotic for treating UTIs in pregnant women, as it is considered safe and effective.
  • Fosfomycin trometamol (3 g single dose) is also an option, but it is recommended only for women with uncomplicated cystitis 1.
  • Cephalosporins, such as cefadroxil (500 mg b.i.d. for 3 days), can be used as an alternative, but the local resistance pattern for Escherichia coli should be considered 1.

Important Considerations

  • Urine culture should be performed before starting antibiotics to confirm the infection and guide treatment.
  • Pregnant women should increase fluid intake, urinate frequently, and practice good hygiene to help prevent UTIs.
  • Follow-up urine cultures after completing antibiotics are recommended to ensure the infection has cleared.
  • Untreated UTIs can progress to pyelonephritis, which poses risks to both mother and baby, including preterm labor and low birth weight.

Clinical Guidelines

The European Association of Urology guidelines on urological infections recommend Nitrofurantoin as a first-line treatment for uncomplicated cystitis in women, including those in the second trimester of pregnancy 1. The Infectious Diseases Society of America guidelines also recommend Nitrofurantoin as a first-line treatment for acute uncomplicated cystitis in women, but note that the optimal duration of antimicrobial therapy for pregnant women has not been determined 1. The U.S. Preventive Services Task Force recommends screening for asymptomatic bacteriuria in pregnant women, as it can help prevent symptomatic urinary tract infections and low birth weight 1.

From the Research

UTI Treatment in Second Trimester Pregnancy

  • The treatment of urinary tract infections (UTIs) during pregnancy is crucial to prevent complications for both the mother and the fetus 2.
  • According to a study published in 1994, limited data are available regarding the appropriate antibiotic management of UTI in pregnancy, but single-dose cure rates with amoxicillin are approximately 80 percent, and trimethoprim/sulfamethoxazole provides cure rates of greater than 80 percent 3.
  • Cephalosporins and nitrofurantoin produce variable results, and it is recommended to separate pregnant subjects with UTI into two groups: those with asymptomatic bacteriuria can be treated with a single dose of an antimicrobial to which the organism is susceptible, and those with symptomatic UTI can be treated with amoxicillin 500 mg tid for three days 3.
  • A study published in 1992 found that postcoital prophylaxis consisting of a single oral dose of either cephalexin (250 mg) or nitrofurantoin macrocrystals (50 mg) is effective in preventing recurrent UTIs during pregnancy 4.
  • Another study published in 2020 recommends the use of nitrofurantoin, fosfomycin, or pivmecillinam as first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females, but the treatment options for UTIs during pregnancy may differ due to the risk of resistance development and the need to consider the safety of the fetus 5.
  • The treatment options for UTIs during pregnancy should be guided by the results of urine cultures and susceptibility testing, and the choice of antibiotic should be based on the severity of the infection, the presence of underlying medical conditions, and the potential risks to the fetus 3, 2.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Recommended treatment for urinary tract infection in pregnancy.

The Annals of pharmacotherapy, 1994

Research

Effective prophylaxis for recurrent urinary tract infections during pregnancy.

Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 1992

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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