“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ACOG Practice Bulletin 47 currently withdrawn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