“Emerging Concepts in Antibiotic Prophylaxis
for Cesarean Delivery “Journal Article Review
Diana S Wolfe, MFM Fellow Year 1Mentor: Dr. Carol Archie
Background
• Prophylactic antibiotics ↓ surgical site infection
• National guidelines recommend administration prior to surgical incision • Cesarean Section is the Exception
Burden Of Disease
Burden of Disease
• Pregnancy-Related Mortality and Morbidity• Infections remain among the top five
causes
• Risk factor for postpartum infection• Cesarean: single most important
risk factor• Most common sites: endometritis
and wound
• Mode of Delivery• Cesareans ↑ risk of postpartum
infection 5-20x
ACOG Practice Bulletin 47 currently withdrawn
• Antibiotic prophylaxis recommended • All who have a cesarean delivery
• Narrow Spectrum Antibiotic• “such as a first-generation
cephalosporin”
Public Health Priority
• Despite Antibiotic Prophylaxis Protocols• 10% of Cesarean Deliveries → Infection• 15% of Cesarean Deliveries → Fever
• This is an Underestimation • 15-80% of postcesarean infections occur
after d/c
• Cesarean Delivery is Rising→ Prevention of Infection is a Public
Health Priority
Methods: Data Collection
• Data Search• January, 1966-July, 2008• “cesarean” and “antibiotic prophylaxis”
• 15 Studies found• Clinical trials/Meta-analysis/Observational studies• Evaluated timing of antibiotics or extended-spectrum prophylaxis
• 9 Studies found• National recommendations/Meta-analyses• Support current standards for antibiotic prophylaxis
• Outcome Measure• Postcesarean maternal infection (endometritis and wound
infection)• Neonatal sepsis and sepsis workups
Pre-incision Antibiotic Prophylaxis
• Administration within 30-60 mins of surgery• Max tissue and blood [antibiotic] at surgical site
• Transfer to fetal compartment• 2 hours for Cefazolin• Concern for fetal exposure to antibiotic
• Mask infection in the neonate• Promote selection of resistant organisms
• Subsequent Decision to Administer Antibiotics• After delivery of the infant and clamping of
cord
Review of Studies
• Two nonrandomized studies • Pre-incision administration did not ↓ infection• It did ↑ neonatal sepsis evaluations and costs
• Three randomized control trials• Prophylactic antibiotics before incision
• Prevent post-cesarean infection• None of the studies had sig power to assess
neonatal sepsis→ 4,800 cesarean deliveries would be needed to
ascertain a 33% difference in neonatal sepsis with 80% power
→ Assuming a baseline incidence of 5%
Timing of Antibiotic Prophylaxis
for Cesarean Delivery
Owens, Stephanie M., et al.
Obstetrics & Gynecology 114(3)
Antimicrobial Prophylaxis for Cesarean Delivery Before Skin Incision
September, 2009
Magee-Women's Hospital
Mitchell, T.F., et. Al. Obstetrics
and Gynecology 2001; 98
Maternal and Transplacental Pharmacokinetics of Cefazolin
2001
University of Michigan
Association of Extended-
Spectrum Antibiotic Prophylaxis
with ↓ Infx• Polymicrobial Infection
• Aerobes/Anaerobes/Ureaplasma [Mycoplasma]
• Most Common Organisms from Wound Infx• Ureaplasma/Staphlococci/Enterococci
• Most Common Organism from Amniotic Fluid• Ureaplasma/Mycoplasma
Extended Spectrum Antibiotic Prophylaxis
• Extended Spectrum Regimen: Both• Standard narrow-spectrum antibiotic • Second antibiotic of a different class i.e.
azithromycin, gentamycin or metronidazole
• Sig more effective in ↓ post-cesarean infx
Studies on Extended-Spectrum Antibiotic Prophylaxis
Annual Incidence of
Postcesarean Endometritis for
Three Periods
Limitations
• Review Findings are Biased• Studies with negative findings not published
• Information re safety of pre-incision prophylactic antibiotics is inconclusive• Effect on Rate of Neonatal Infections• Emergence of Antimicrobial resistance• Selection of Known Resistant Organisms
• Extended-Spectrum Data• Single Centers with Varied Regimens
Conclusion
• Use of Cefazolin alone before incision or Extended-Spectrum regimen after cord clamp→ Association with ↓ Post-cesarean
Maternal Infx
• Future Studies• Neonatal Outcomes• Comparing Time of Antibiotic
Administration