UTI in pregnancy

from eTG

Asymptomatic Bacteriuria in Pregnancy

• More than 100,000 colony-forming units/mL without symptoms of UTI, generally indicates asymptomatic bacteriuria.
• A bacteria count of more than 100,000 colony-forming units/mL with 2 or more organisms may indicate contamination rather than bacteriuria
• Risk and Complications:
  • Untreated bacteriuria increases the risk of developing pyelonephritis by 20-30% due to physiological changes in the urinary tract during pregnancy.
  • Associated with adverse pregnancy outcomes such as preterm birth and low birth weight.
• Benefit of Treatment:
  • Antibiotic treatment reduces the risk of symptomatic urinary tract infection (UTI) during pregnancy.
• Screening:
  • Obtain a urine sample for culture and susceptibility testing at 12-16 weeks gestation or at the first antenatal visit if later.
  • Confirm asymptomatic bacteriuria with a second urine culture.
• Treatment:
  • Treat pregnant women with confirmed asymptomatic bacteriuria using susceptibility results to guide therapy.
  • Suitable regimens may include those used for acute cystitis in pregnancy.
• Follow-up:
  • Confirm resolution of infection by repeating urine culture 1-2 weeks after treatment completion.
  • If persistent bacteriuria is identified, refer to guidelines for recurrent UTI and bacteriuria in pregnancy.
• Special Consideration:
  • If Streptococcus agalactiae (group B streptococcus [GBS]) is detected, intrapartum prophylaxis for GBS is usually indicated (refer to guidelines on the prevention of neonatal GBS disease).

Acute Cystitis in Pregnancy

• Diagnosis:
  • Obtain urine samples for culture and susceptibility testing before initiating antibiotic therapy.
• Empirical Therapy (pending culture results):
  • Nitrofurantoin: 100 mg orally, 6-hourly for 5 days (Note: An alternative regimen is 100 mg 12-hourly for 5 days; avoid close to delivery due to risk of neonatal jaundice and hemolytic anemia).
  • Cefalexin: 500 mg orally, 12-hourly for 5 days.
  • Trimethoprim: 300 mg orally, daily for 3 days (safe in the second and third trimesters; avoid if used within the previous 3 months or if resistant E. coli isolated).
• Alternative Therapy (if pathogen resistant):
  • Amoxicillin: 500 mg orally, 8-hourly for 5 days.
  • Amoxicillin + Clavulanate: 500+125 mg orally, 12-hourly for 5 days.
• Follow-up:
  • Confirm infection resolution by repeating urine culture 1-2 weeks post-treatment.
  • If persistent bacteriuria is identified, refer to guidelines for recurrent UTI and bacteriuria in pregnancy.
• Special Consideration:
  • If GBS is detected in urine at any stage of pregnancy, intrapartum prophylaxis for GBS is usually indicated.

Acute Pyelonephritis in Pregnancy

• Complications:
  • Acute pyelonephritis is associated with adverse maternal and fetal outcomes, including preterm labor, low birth weight, and sepsis.
• Empirical Therapy (pending culture results):
  • Gentamicin: intravenously (refer to principles of aminoglycoside use for dosage).
  • Plus either Amoxicillin or Ampicillin: 2 g intravenously, 6-hourly.
• Alternative Therapy:
  • If gentamicin is contraindicated, use Ceftriaxone 1 g intravenously, daily or Cefotaxime 1 g intravenously, 8-hourly.
  • For penicillin hypersensitivity, use gentamicin as a single drug for empirical therapy.
• Modification of Therapy:
  • Modify based on culture results by 72 hours.
  • If empirical intravenous therapy is still required after 72 hours, switch from gentamicin to ceftriaxone or cefotaxime.
• Switch to Oral Therapy:
  • Switch to oral therapy once the patient is clinically stable.
  • Oral therapy should be based on culture and susceptibility results.
  • Suitable oral regimens include:
    • Amoxicillin: 500 mg orally, 8-hourly.
    • Cefalexin: 500 mg orally, 6-hourly.
    • Amoxicillin + Clavulanate: 875+125 mg orally, 12-hourly.
    • Trimethoprim: 300 mg orally, daily (safe in second and third trimesters).
• Duration of Therapy:
  • Total duration of therapy (IV + oral) is 10-14 days, depending on clinical response.
• Follow-up:
  • Confirm infection resolution by repeating urine culture 1-2 weeks post-treatment.
  • If persistent bacteriuria is identified, refer to guidelines for recurrent UTI and bacteriuria in pregnancy.
• Special Consideration:
  • If GBS is detected in urine, intrapartum prophylaxis for GBS is usually indicated.

Recurrent UTI and Bacteriuria in Pregnancy

• Monitoring:
  • Perform repeat urine culture at antenatal visits to monitor for recurrent bacteriuria.
• Treatment:
  • Choose treatment based on culture and susceptibility results (refer to guidelines for acute cystitis in pregnancy).
• Acute Episode:
  • Treat recurrent UTI as for cystitis or pyelonephritis, as appropriate.
• Prophylaxis for Recurrent Cases:
  • Consider antibiotic prophylaxis for pregnant women with recurrent bacteriuria or risk factors for pyelonephritis (e.g., immune compromise, diabetes, neurogenic bladder).
  • Prophylactic regimens:
    • Cefalexin: 250 mg orally, at night for the remainder of pregnancy.
    • Nitrofurantoin: 50 mg orally, at night for the remainder of pregnancy (avoid close to delivery).
• Considerations:
  • Always consider the safety of antimicrobials in pregnant women.