Group B streptococcus screening and prophylaxis

1. Screening Protocol

• Timing: Universal rectovaginal swab at 36 0/7 – 37 6/7 weeks GA.
• Skip screening & give automatic IAP if:
  • Prior infant with invasive GBS disease.
  • GBS bacteriuria/UTI at any point during the current pregnancy.

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2. Indications for Intrapartum Antibiotic Prophylaxis (IAP)

• (+) GBS culture at 36–37 weeks.
• GBS bacteriuria/UTI in current pregnancy.
• Prior infant with early-onset GBS.
• Unknown GBS status PLUS $\ge 1$ risk factor:
  • Preterm delivery (< 37 weeks).
  • ROM $\ge 18$ hours.
  • Maternal temp $\ge 38.0^{\circ }\text{C}$ (100.4${}^{\circ }\text{F}$) $\to$ Treat for chorioamnionitis (IV Amp + Gent).
  • (+) Intrapartum GBS NAAT/PCR.

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3. No IAP Indicated

• Planned Cesarean delivery before labor onset with intact membranes (even if GBS (+)).
• (-) GBS screen in current pregnancy (even with prolonged ROM or preterm labor, unless chorioamnionitis develops).
• GBS (+) in a prior pregnancy with a negative current screen.

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4. Antibiotic Selection (Must be IV, $\ge 4$ hours before delivery)

• 1st-Line: IV Penicillin G (or IV Ampicillin).
• PCN Allergy (Low Risk / Mild rash): IV Cefazolin. c
• PCN Allergy (High Risk / Anaphylaxis):
  • Clindamycin-susceptible $\to$ IV Clindamycin.
  • Clindamycin-resistant OR unknown susceptibility $\to$ IV Vancomycin.

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5. Postnatal Neonatal Management

• Symptomatic Infant: Full sepsis workup (CBC, Blood Cx, LP, CXR) + IV Ampicillin + Gentamicin.
• Asymptomatic + Chorioamnionitis: CBC, Blood Cx + observe $\ge 48$ hrs $\pm$ Abx.
• Asymptomatic + Inadequate IAP (< 4 hrs):
  • < 37 weeks OR ROM $\ge 18$ hrs $\to$ CBC, Blood Cx + observe $\ge 48$ hrs.
  • $\ge 37$ weeks AND ROM < 18 hrs $\to$ Observe $\ge 48$ hrs (no labs).
• Asymptomatic + Adequate IAP ($\ge 4$ hrs): Routine care + observe $\ge 48$ hrs (discharge at 24 hrs if low-risk term).