Treatment of Asymptomatic Bacteriuria in Pregnant Women
Yes, treatment of asymptomatic bacteriuria is strongly recommended for pregnant women, including those with cloudy urine appearance and bacteria count of 420.2/uL, as this significantly reduces the risk of pyelonephritis and adverse pregnancy outcomes. 1, 2
Rationale for Treatment
- Pregnant women with untreated asymptomatic bacteriuria have a 20-30 fold increased risk of developing pyelonephritis compared to women without bacteriuria 1, 2
- Treatment decreases the risk of pyelonephritis from 20-35% to 1-4% 1, 2
- Treatment also reduces the risk of preterm delivery and low birth weight infants 1, 2
- Implementation of screening and treatment programs has demonstrated significant reductions in pyelonephritis rates in pregnant women, from 1.8% to 0.6% and from 2.1% to 0.5% in different healthcare centers 1
Diagnostic Considerations
- The diagnosis of asymptomatic bacteriuria should be based on urine culture, which is the gold standard 1, 2
- For asymptomatic women, bacteriuria is defined as 2 consecutive voided urine specimens with isolation of the same bacterial strain in quantitative counts ≥10^5 CFU/mL 1
- A single catheterized urine specimen with 1 bacterial species isolated in a quantitative count ≥10^2 CFU/mL also identifies bacteriuria 1
- Pyuria alone (presence of white blood cells in urine) is not a reliable indicator for treatment decisions in pregnancy 2
Treatment Recommendations
- Treat with a 3-7 day course of antimicrobial therapy based on culture and sensitivity results 1, 2
- First-line treatment options include:
- Nitrofurantoin 100mg BID
- Cephalexin 500mg QID
- Ampicillin 500mg QID (if susceptible) 2
- Avoid fluoroquinolones, tetracyclines, and trimethoprim-sulfamethoxazole in the first and third trimesters 2
- Short-course (4-7 day) regimens are more effective than single-dose treatments for cure of asymptomatic bacteriuria 3
Follow-up Protocol
- Obtain follow-up urine culture 1-2 weeks after completing therapy to ensure clearance of bacteriuria 2
- If bacteriuria persists, retreat with a different antibiotic based on susceptibility testing 2
- Periodic screening for recurrent bacteriuria should be undertaken following therapy 1
Common Pitfalls to Avoid
- Inadequate screening: All pregnant women should be screened for asymptomatic bacteriuria at least once in early pregnancy, optimally at 12-16 weeks gestation 1, 2
- Insufficient treatment duration: Single-dose therapy is less effective than short-course (4-7 day) regimens 3
- Inappropriate antibiotic selection: Choose antibiotics based on culture and sensitivity results when available 2
- Failure to follow up: Follow-up cultures are essential to confirm cure 2
- Relying on dipstick testing alone: Dipstick testing for pyuria has low sensitivity (approximately 50%) and should not replace urine culture 2
The evidence consistently supports treating asymptomatic bacteriuria in pregnant women as a standard of care to prevent serious complications that can affect both maternal and fetal health outcomes.