1. “Emerging Concepts in Antibiotic Prophylaxis for Cesarean Delivery “ Journal Article Review Diana S Wolfe, MFM Fellow Year 1 Mentor: Dr. Carol Archie

2. Background Prophylactic antibiotics ↓ surgical site infection National guidelines recommend administration prior to surgical incision Cesarean Section is the Exception

3. Burden Of Disease

4. 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

5. ACOG Practice Bulletin 47 currently withdrawn Antibiotic prophylaxis recommended All who have a cesarean delivery Narrow Spectrum Antibiotic “such as a first-generation cephalosporin”

6. 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

7. 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

8. 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

9. 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%

10. Timing of Antibiotic Prophylaxis for Cesarean Delivery

11. Owens, Stephanie M., et al. Obstetrics & Gynecology 114(3) Antimicrobial Prophylaxis for Cesarean Delivery Before Skin Incision September, 2009 Magee-Women's Hospital

12. Mitchell, T.F., et. Al. Obstetrics and Gynecology 2001; 98 Maternal and Transplacental Pharmacokinetics of Cefazolin 2001 University of Michigan

13. 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

14. 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

15. Studies on Extended-Spectrum Antibiotic Prophylaxis

16. Annual Incidence of Postcesarean Endometritis for Three Periods

17. 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

18. 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