SUMMARY:

Timing is of paramount importance when considering the use of antibiotics during labor and delivery because the goal is to have adequate tissue levels before exposure to a pathogen. ACOG provides guidance on this topic, summarized below.

• Cesarean Delivery Antibiotic Prophylaxis
• Skin and Vaginal Preps
• MRSA Colonization
• PPROM
• Preterm Labor – Intact Membranes
• Prophylaxis for Bacterial Endocarditis
• Other Clinical Scenarios

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

Notes 

• 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

KEY POINTS:  

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

PPROM

<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

Related ObG Topics:

Updated Guidance on GBS Screening and Prophylaxis

Guidance Update: Diagnosis and Management of PROM (Prelabor Rupture of Membranes)

Azithromycin Prophylaxis to Reduce Infection Risk Post C-Section

Preventing Infection: Optimizing Antibiotic Regimen Post- C-Section in Obese Women

What Risk Factors Increase Likelihood of C-Section Infection?

Preventing Gynecologic Post-Procedure Infection