What is the recommended liquid antibiotic treatment for a 25-week pregnant female with a Group B strep (Streptococcus agalactiae) urinary tract infection (UTI)?

Treatment of Group B Streptococcal UTI at 25 Weeks Gestation Requiring Liquid Antibiotic

For a 25-week pregnant woman with GBS UTI requiring liquid antibiotic, treat the acute UTI immediately with an appropriate oral antibiotic suspension (such as amoxicillin suspension 500 mg every 8 hours for 7-10 days), and document that she will require mandatory intrapartum IV antibiotic prophylaxis during labor regardless of current treatment. 1

Immediate UTI Treatment (Now, at 25 Weeks)

• Treat the acute UTI with standard pregnancy-safe oral antibiotics in liquid formulation 1, 2
• Amoxicillin suspension 500 mg every 8 hours for 7-10 days is the preferred first-line liquid antibiotic 2
• Penicillin VK suspension 500 mg every 6 hours for 7-10 days is an acceptable alternative 2
• Complete the full prescribed course to ensure eradication and prevent recurrence 1

For Penicillin-Allergic Patients (Non-Severe Allergy)

• Cephalexin suspension 500 mg every 6 hours is the preferred alternative for patients without history of anaphylaxis, angioedema, respiratory distress, or urticaria 2, 3
• This applies only to patients with non-severe penicillin allergy (e.g., rash without systemic symptoms) 3

For High-Risk Penicillin Allergy

• Clindamycin suspension 300-450 mg every 6 hours orally, but ONLY if susceptibility testing confirms the GBS isolate is susceptible 2
• Request susceptibility testing for clindamycin and erythromycin on the GBS isolate 1
• Resistance to clindamycin ranges from 3-15% in GBS isolates, making susceptibility testing essential 4

Critical Understanding: Why Intrapartum Prophylaxis is Still Required

• GBS bacteriuria at any concentration during pregnancy is a marker for heavy genital tract colonization and significantly increases the risk of early-onset neonatal GBS disease 1
• Treating the UTI now does NOT eliminate GBS colonization from the genitourinary tract—recolonization after oral antibiotics is typical 1
• All pregnant women with GBS bacteriuria at any point during pregnancy must receive intrapartum IV antibiotic prophylaxis during labor, regardless of whether the UTI was treated earlier 1, 4
• This is a common and dangerous error to assume that treating the UTI eliminates the need for intrapartum prophylaxis 1

Intrapartum Prophylaxis (During Labor, Months from Now)

• Penicillin G 5 million units IV initially, then 2.5-3.0 million units IV every 4 hours until delivery is the preferred intrapartum regimen 4, 1
• Ampicillin 2 g IV initially, then 1 g IV every 4 hours until delivery is an acceptable alternative 4, 1
• Intrapartum prophylaxis must be administered ≥4 hours before delivery for maximum effectiveness (78% reduction in early-onset neonatal GBS disease) 1

Intrapartum Alternatives for Penicillin Allergy

• For non-high-risk allergy: Cefazolin 2 g IV initially, then 1 g IV every 8 hours until delivery 4, 3
• For high-risk allergy with susceptible isolate: Clindamycin 900 mg IV every 8 hours until delivery 4, 3
• For high-risk allergy with resistant or unknown susceptibility: Vancomycin 1 g IV every 12 hours until delivery 4, 3

Essential Documentation and Follow-Up

• Document in the prenatal record that this patient had GBS bacteriuria at 25 weeks and requires intrapartum prophylaxis 1
• Communicate this finding to the anticipated site of delivery 1
• This patient does NOT need repeat vaginal-rectal GBS screening at 36-37 weeks, as she is presumed to be GBS colonized 1
• Repeat urine culture 7 days after completing antibiotic treatment to confirm cure 5

Critical Pitfalls to Avoid

• Never assume that treating the UTI eliminates the need for intrapartum prophylaxis—this is the most dangerous error 1, 2
• Do not underdose or allow premature discontinuation of the current UTI treatment, as this leads to treatment failure and recurrence 1, 2
• Do not attempt to "decolonize" the patient with prolonged antibiotic courses outside of treating active infection—this is ineffective and promotes resistance 2, 4
• Ensure laboratory reports of GBS bacteriuria are communicated to both the delivery site and ordering provider 1