From the Guidelines
Urinary tract infections (UTIs) with bacterial counts exceeding 50,000 CFU during pregnancy should be treated promptly with antibiotics, even if asymptomatic, to prevent complications like pyelonephritis and adverse pregnancy outcomes.
Treatment Options
- First-line treatment typically includes amoxicillin-clavulanate 500/125 mg orally three times daily for 7 days, or cephalexin 500 mg orally four times daily for 7 days, as recommended by the Infectious Diseases Society of America guidelines 1.
- Alternative options for penicillin-allergic patients include nitrofurantoin 100 mg orally twice daily for 7 days (avoid in third trimester or near delivery) or fosfomycin 3 g single oral dose.
- Trimethoprim-sulfamethoxazole should be avoided in the first and third trimesters due to the potential risk of kernicterus and other adverse effects.
Rationale
- Treatment is essential because pregnancy causes physiological changes that increase UTI risk, including urinary stasis from progesterone-induced smooth muscle relaxation and mechanical compression of the ureters by the enlarging uterus.
- Prompt treatment of UTIs during pregnancy can reduce the risk of pyelonephritis and adverse pregnancy outcomes, such as preterm delivery and low birth weight 1.
- A prospective, controlled trial randomized bacteriuric women to receive a 1-week course of therapy with nitrofurantoin, which resulted in a significant reduction in the risk of pyelonephritis and adverse pregnancy outcomes 1.
Additional Recommendations
- Treatment should be guided by culture and sensitivity results when available.
- Following treatment, a test-of-cure urine culture is recommended 1-2 weeks after completing antibiotics to confirm resolution.
- Pregnant women should also increase fluid intake, urinate frequently, and practice good hygiene to reduce the risk of UTIs.
- The American College of Physicians recommends following the IDSA/ATS guidelines for clinical stability, which includes prescribing short-course antibiotics for uncomplicated UTIs 2.
From the Research
Treatment Options for UTI during Pregnancy
- For uncomplicated UTIs in pregnant women, oral antibacterial therapy (ABT) is recommended, with options including nitrofurans, fosfomycin trometamol, and third-generation cephalosporins 3.
- Cefixime is considered a rational choice due to its high sensitivity to the main uropathogens (E. coli), high efficiency, safety, and compliance with treatment in pregnant women 3.
- A systematic review and meta-analysis found that single-dose oral fosfomycin (300 mg) and nitrofurantoin (100 mg for 5 days) are effective and safe treatment options for uncomplicated UTI in women, with no significant differences in clinical and microbiological cure rates 4.
Antibiotic Resistance and Treatment
- The treatment of UTIs caused by antibiotic-resistant Gram-negative bacteria is a growing concern, and knowledge of local susceptibility patterns is essential in determining appropriate empiric antibiotic therapy 5.
- For UTIs due to ESBL-producing Enterobacteriales, treatment options include nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin, while parenteral treatment options include piperacillin-tazobactam, carbapenems, and ceftazidime-avibactam 5.
Prevention of Recurrent UTIs during Pregnancy
- Postcoital prophylaxis with a single oral dose of either cephalexin (250 mg) or nitrofurantoin macrocrystals (50 mg) is effective in preventing recurrent UTIs during pregnancy 6.
- Nitrofurantoin is also recommended for UTI prophylaxis, but its use should be avoided at the end of pregnancy due to the risk of kernicterus for the neonate 7.
Diagnosis and Treatment of UTI during Pregnancy
- The diagnosis of UTI is microbiological, based on two urine cultures presenting more than 10^5 colonies/mL urine of the same germ 7.
- Treatment should be based on an antibiogram, and previous knowledge of the resistance profile of the antibacterial agents available for the treatment of pregnant women is essential 7.
- For the treatment of pyelonephritis, an intravenous bactericidal antibiotic should be used during the acute phase, with the possibility of oral administration at home after clinical improvement of the patient 7.