Management of Pyuria in Pregnancy
Pregnant women with pyuria should be screened for asymptomatic bacteriuria with urine culture and treated if positive, as this significantly reduces the risk of pyelonephritis and adverse pregnancy outcomes. 1
Diagnosis and Screening
- All pregnant women should be screened for bacteriuria with urine culture at least once during early pregnancy (12-16 weeks gestation or at first prenatal visit if later) 1
- Pyuria alone (without bacteriuria) is not an indication for antimicrobial treatment 1
- For diagnosis of asymptomatic bacteriuria in pregnant women, two consecutive voided urine specimens with isolation of the same bacterial strain in quantitative counts ≥10^5 CFU/mL are required 1
- Urine culture is the gold standard for detecting bacteriuria in pregnancy; dipstick testing has poor predictive value 2
Treatment Recommendations
- For pregnant women with asymptomatic bacteriuria, antimicrobial treatment for 4-7 days is recommended rather than single-dose therapy 1
- Beta-lactam antibiotics (ampicillin, cephalexin) and nitrofurantoin are preferred due to their safety profile in pregnancy 2
- Fluoroquinolones and tetracyclines are contraindicated during pregnancy 3, 2
- Trimethoprim-sulfamethoxazole should generally be avoided in the first trimester due to potential folate antagonism 3, 2
Duration of Treatment
- The recommended duration of antimicrobial therapy for asymptomatic bacteriuria in pregnancy is 4-7 days 1
- Single-dose therapy may be less effective than 7-day regimens for treating asymptomatic bacteriuria in pregnancy 4
- A Cochrane review showed that 7-day therapy was more effective than single-dose therapy in preventing adverse outcomes such as low birth weight 1
Follow-up After Treatment
- Periodic screening for recurrent bacteriuria should be undertaken following therapy 1
- Some experts recommend continued screening throughout pregnancy after treatment of bacteriuria 3
- Untreated bacteriuria in pregnancy carries a 20-30 fold increased risk of developing pyelonephritis compared to non-pregnant women 3, 5
Management of Symptomatic UTI in Pregnancy
- For symptomatic lower UTI (cystitis), treatment options include:
- For pyelonephritis, initial intravenous therapy is recommended with extended-spectrum cephalosporins or penicillins 3
- Treatment duration for pyelonephritis should be 10-14 days 3
Clinical Considerations and Pitfalls
- Asymptomatic bacteriuria occurs in 2-7% of pregnant women 1
- Untreated asymptomatic bacteriuria can lead to pyelonephritis in 20-35% of pregnant women 1
- Pyuria is common in healthy non-pregnant women and rarely associated with bacteriuria or symptoms, supporting recommendations not to treat pyuria without bacteriuria 8
- Escherichia coli is the most common pathogen isolated from pregnant women with UTIs 5
- Failing to treat bacteriuria in pregnancy can lead to increased risk of preterm delivery and low birth weight infants 2, 5