Is Group B Streptococcus (GBS) prophylaxis still necessary for a pregnant woman undergoing a planned cesarean delivery?

GBS Prophylaxis Not Needed for Planned Cesarean Delivery with Intact Membranes

Intrapartum antibiotic prophylaxis for Group B Streptococcus (GBS) is not recommended for women undergoing planned cesarean deliveries performed before labor onset with intact amniotic membranes, regardless of GBS colonization status or gestational age. 1, 2

Rationale for Omitting GBS Prophylaxis in Planned Cesarean

• The risk of GBS transmission during planned cesarean delivery with intact membranes is extremely low 1
• CDC guidelines explicitly state that intrapartum antibiotic prophylaxis to prevent early-onset GBS disease is not indicated in this specific circumstance 1
• Standard surgical prophylaxis for cesarean delivery should still be administered according to usual protocols, but this is not affected by GBS status 2

Important Exceptions - When GBS Prophylaxis IS Needed

GBS prophylaxis should still be administered if any of these occur:

• Labor begins before the cesarean delivery
• Rupture of membranes occurs before the cesarean delivery
• Any other risk factors develop:
  • Maternal fever ≥100.4°F (≥38.0°C)
  • Rupture of membranes ≥18 hours
  • Delivery at <37 weeks' gestation 1

Screening Recommendations

Despite not needing prophylaxis for planned cesarean with intact membranes:

• Women expected to undergo planned cesarean deliveries should still undergo routine vaginal and rectal screening for GBS at 35-37 weeks' gestation 1, 2
• This is because labor or rupture of membranes may occur before the planned cesarean delivery, which would then necessitate GBS prophylaxis if the woman is colonized 1

Clinical Algorithm for GBS Management in Cesarean Delivery

1. Obtain GBS screening at 35-37 weeks for all pregnant women, including those planning cesarean delivery
2. Assess at time of delivery:
   • If cesarean is performed before labor onset with intact membranes: No GBS prophylaxis needed
   • If labor begins or membranes rupture before cesarean: Administer GBS prophylaxis if woman is GBS positive
3. Administer standard surgical prophylaxis for cesarean delivery regardless of GBS status

Potential Pitfalls to Avoid

• Do not confuse standard surgical prophylaxis for cesarean delivery with GBS-specific prophylaxis - they serve different purposes
• Do not omit GBS screening in women planning cesarean delivery, as circumstances may change requiring GBS prophylaxis
• Remember that if chorioamnionitis is suspected, broad-spectrum antibiotic therapy that includes coverage for GBS should be administered regardless of planned delivery mode 1

This evidence-based approach balances the extremely low risk of GBS transmission during planned cesarean with intact membranes against the potential risks of unnecessary antibiotic exposure, while ensuring appropriate prophylaxis when indicated.