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ACOG Guidance: Antibiotic Prophylaxis during Labor and Delivery


ACOG has released a Practice Bulletin on the role of prophylactic antibiotics in labor and delivery. Timing is of paramount importance because the goal is to have adequate tissue levels before exposure to a pathogen

Cesarean Section Antibiotic Prophylaxis  

Prophylaxis Recommendation 

  • All cesarean deliveries unless already on equivalent broad spectrum coverage  
    • Administer within 60 minutes before the start of the cesarean delivery  
  • If not possible (e.g., emergency surgery)
    • Administer as soon as possible after the incision

Weight Adjusted Dosing (IV route) 

  • No Allergy  
    • Normal BMI (weight ≤80 kg) 
      • 1 g cefazolin   
    • Obese: BMI ≥30 or weight ≥80 kg 
      • 2 g cefazolin
  • Allergy (anaphylaxis, angioedema, respiratory distress, or urticaria)
    • 900 mg clindamycin and 5 mg/kg aminoglycoside


  • Some hospitals may standardize a 2 g cefazolin dose for all patients  
  • For non-obstetric patients, consensus opinion is 2 g cefazolin for patients ≥80 kg and 3 g cefazolin for patients ≥120 kg
    • Data conflicting on 2 vs 3 g cefazolin dosing in obstetric population
    • Increasing the dose to 2 g for ≥80 kg is recommended
    • Benefit of increasing to 3 g for ≥120 kg is not yet established
  • There is evidence that azithromycin may be an alternative or adjunct to first-generation cephalosporins  
    • Adding 500 mg azithromycin, infused over 1 hour, ‘may be considered’ for women undergoing nonelective cesarean  
  • Obesity and postcesarean prophylaxis   
    • Consider postoperative oral regimen in obese individuals who may not have received IV azithromycin 
      • 500-mg oral cephalexin and 500-mg metronidazole every 8 hours for 48 hours
  • Long procedure greater than 2 drug half-lives (>4 hours for cefazolin from time of dose)
    • Administer additional intraoperative dose of the same antibiotic
  • Excessive blood loss >1,500 ml
    • Administer additional intraoperative dose of the same antibiotic


Skin and Vaginal Preps  

Skin Prep Prior to Cesarean  

  • CDC recommends preop skin cleansing prior to cesarean  
  • Use alcohol-based solution unless contraindicated  
  • ‘Reasonable’ choice (ACOG): chlorhexidine-alcohol skin prep  

Vaginal Cleansing Before Cesarean ‘May be Considered

  • In laboring patients and those with ruptured membranes 
  • Use povidine-iodine or chlorhexidine gluconate  
  • Chlorhexidine gluconate 
    • High alcohol concentration contraindicated 
    • Low alcohol (e.g., 4%) concentration, are ‘safe and effective for off-label use’  
    • Consider for women with allergy to iodine-based products or surgeon preference

MRSA Colonization

  • Oral antibiotics are not routinely recommended for MRSA decolonization
  • Routine MRSA screening is not recommended
  • In patients with known MRSA colonization undergoing cesarean
    • ‘consideration’ may be given to adding a single dose of vancomycin to the recommended antibiotic prophylaxis regimen
    • Vancomycin alone is not sufficient coverage for cesarean


<34w0d: Latency Antibiotics are Recommended  

  • Eunice Kennedy Shriver NICHD MFMU Network trial regimen
    • IV ampicillin [2 g every 6 hours] and erythromycin [250 mg every 6 hours] for 2 days followed by oral amoxicillin [250 mg every 8 hours] and erythromycin base [333 mg every 8 hours] for 5 days (total 7 days)
  • Amoxicillin–clavulanic acid
    • Not recommended due to increased risk for necrotizing enterocolitis
  • Allergy to β-lactam antibiotics
    • Not well studied but erythromycin alone may be an alternative
    • Unclear as to whether cerclage, if present, should be removed or retained but if retained, antibiotic therapy should not be extended beyond 7 days

CDC GBS Recommendations

  • Screen women with PPROM for GBS on admission
  • If patient completes 7-day course of latency antibiotics and no infection or labor
    • Manage intrapartum GBS prophylaxis based on GBS test at the time of preterm PROM
  • If patient remains pregnant 5 or more weeks after a negative baseline GBS test
    • Repeat GBS screening
  • If baseline test positive
    • Do not repeat test
    • Administer GBS prophylaxis as per protocol (see ‘Related ObG Topics’ below)

Preterm Labor – Intact Membranes

  • Do not use antibiotics to prolong pregnancy
  • GBS prophylaxis
    • Administer until GBS results return and then manage accordingly
    • If GBS positive on admission but patient does not go in to labor, discontinue until onset of labor
    • GBS prophylaxis not required if patient has a negative GBS result within the previous 5 weeks

Prophylaxis for Bacterial Endocarditis

  • Generally not recommended for vaginal or cesarean delivery
  • Recommended only for vaginal delivery in women with cardiac disease that carries the highest risk of adverse outcomes (American College of Cardiology and American Heart Association) including
    • Congenital heart disease (CHD)
      • Unrepaired cyanotic cardiac disease
      • Completely repaired CHD, using prosthetic material or device
      • Repaired CHD with residual defects at the site or adjacent to the site of a prosthetic patch or device
    • Prosthetic valves
    • Previous infectious endocarditis
    • Cardiac transplant recipients with valve regurgitation to abnormal valve
  • If antibiotic prophylaxis appropriate, administer 30-60 min prior to procedure
  • Mitral valve prolapse does not require prophylaxis

High Risk IV Regimen 

  •  No allergy
    • Ampicillin 2 g IV or
    • Cefazolin or ceftriaxone 1 g IV
  • Allergy to penicillin or ampicillin
    • Cefazolin or ceftriaxone 1 g IV or
    • Clindamycin 600 mg IV

High Risk PO Regimen

  • No allergy
    • Amoxicillin 2 g PO
  • Allergy to penicillin or ampicillin
    • Cephalexin 2 g PO or
    • Clindamycin 600 mg or
    • Azithromycin 500 mg

Other Clinical Scenarios

Other Obstetric Procedures

  • Manual removal of placenta following vaginal delivery
    • Data lacking but common to provide prophylactic antibiotics due to high risk of infection
  • Postpartum D&C
    • No data to recommend for or against prophylactic antibiotics
  • Indwelling balloon catheter for management of PPH or retained placenta
    • No data to recommend for or against prophylactic antibiotics
  • Cerclage
    • Evidence is insufficient to recommend for or against prophylactic antibiotics
  • 3rd and 4th degree lacerations
    • Single dose of antibiotic at the time of repair ‘is reasonable’
    • Based on 1 RCT that demonstrated benefit with cefotetan or cefoxitin, 1 g intravenously, or clindamycin, 900 mg intravenously, if allergic to penicillin

Learn More – Primary Sources:

ACOG Practice Bulletin 199: Use of Prophylactic Antibiotics in Labor and Delivery