II. Epidemiology
- Asymptomatic Bacteriuria in 2 to 7% of pregnancies
- Significant cause of Preterm Labor
III. Causes: Bacteria
- Escherichia coli (most common, up to 82% of Pyelonephritis cases)
- Klebsiella
- Proteus miribilis
- Pseudomonas aeruginosa
- Enterobacter
- Staphylococcus saprophyticus
- Enterococcus
- Group B Streptococcus
IV. History
- Dysuria
- Urinary Frequency
- Urinary Urgency
- Suprapubic Pain
- Symptoms suggestive of Pyelonephritis
- Past Medical History
- Kidney Stones
- Cystitis
- Pyelonephritis
- Sickle Cell Trait
- Predisposes to Pyelonephritis
V. Signs of cystitis (Contrast with Pyelonephritis)
- Afebrile
- Suprapubic Pain
- No Costovertebral angle (CVA) tenderness
VI. Complications
- Pyelonephritis (20-40% of untreated bacteriuria)
-
Preterm Labor
- Associated with bacteruria
- Confirm with Urine Culture for cure after Urinary Tract Infection treatment
- Consider periodic repeat Urine Culture
VII. Labs
-
Urinalysis
- Screen all women at first Prenatal Visit
- If negative, then screen later only for symptoms
-
Urine Culture with Sensitivity
- Strongly consider Urinary Catheter specimen
- Indicated for recurrent mixed Bacterial species
- UTI or Asymptomatic Bacteriuria criteria
- Single Bacterial species >50,000 colonies
- Group B Streptococcus at any count
- Strongly consider Urinary Catheter specimen
VIII. Management: Acute Cystitis and Asymptomatic Bacteriuria
-
Antibiotic Course:
- Initial 10 days
- Recurrent 14-21 days
- Repeat Urine Culture one month after treatment
- Asymptomatic bacteruria found on repeat Urine Culture
- Confirm not vaginal contaminant (squamous epithelial cells present)
- Especially for mixed Bacterial flora
- Consider Urinary Catheter specimen
- Repeat Urine Culture monthly
- Treat with Antibiotics for an additional 10 days
- Consider low dose prophylaxis to 2 weeks postpartum
- Indicated for 2 episodes Asymptomatic Bacteriuria
- Confirm not vaginal contaminant (squamous epithelial cells present)
- First Line Antibiotics in Pregnancy
- Nitrofurantoin
- First trimester use is weakly and inconsistently associated with heart defects and Cleft Lip
- Avoid after 36-38 weeks due to newborn Hemolytic Anemia risk
- Macrodantin 100 mg PO tid-qid
- Macrobid 100 mg PO bid
- Safe Antibiotics in any trimester
- Cephalexin (Keflex) 500 mg orally twice daily
- Fosfomycin (Monurol)
- Expensive, single dose option that may be useful in resistant infections
- Other Antibiotics
- Amoxicillin-Clavulanate (Augmentin) 875 mg orally twice daily
- Cefixime (Suprax) 400 mg orally daily
- Cefpodoxime 200 mg orally twice daily
- Ceftin (Cefuroxime) 125-250 mg orally twice daily
- Nitrofurantoin
- Other agents with lower efficacy (60% against E. coli, consider if sensitive on culture)
- Ampicillin 250-500 mg PO qid
- Amoxicillin 250-500 mg PO tid or
- Amoxicillin 3 grams PO for 1 dose
- Other agents with safety precautions
- Trimethoprim-Sulfamethoxazole
- Consider for use in second and early third trimester
- Risk of Neural Tube Defects in first trimester
- Hyperbilirubinemia (and Kernicterus risk) in late third trimester
- Trimethoprim-Sulfamethoxazole
IX. Management: Urinary Tract Infection Prophylaxis
- Macrodantin 50 to 100 mg orally at bedtime (do not use after 38 weeks)
- Cephalexin (Keflex) 250-500 mg orally at bedime