Timing of Preoperative Antibiotic Administration for Cesarean Section in PPROM
Antibiotics should be administered within 60 minutes before skin incision, with the optimal window being 30-60 minutes prior to the start of surgery. 1
Recommended Timing
The correct answer is B: 60 minutes before incision (or within the 30-60 minute window).
The Enhanced Recovery After Surgery (ERAS) Society guidelines for cesarean delivery explicitly state that intravenous antibiotics should be administered routinely within 60 minutes before the cesarean delivery skin incision, with high-quality evidence and a strong recommendation grade. 1 The guidelines specifically emphasize that the preoperative dose should be given 30-60 minutes prior to the start of surgery to ensure adequate antibiotic levels are present in the serum and tissues at the time of initial surgical incision. 1
Rationale for Pre-Incision Timing
Historical practice has shifted: Previously, antibiotics were given after cord clamping due to concerns about fetal exposure, but current evidence demonstrates that pre-incision administration decreases wound infections without causing fetal harm. 1
PPROM represents a higher-risk scenario: A cesarean delivery with ruptured membranes is classified as a clean-contaminated (class II) or potentially contaminated (class III) incision, carrying increased risk from both skin flora and vaginal flora exposure. 1
Antibiotic Selection for PPROM
First-generation cephalosporin (cefazolin) is the primary choice for all women undergoing cesarean section. 1
Addition of azithromycin is recommended in women in labor or with ruptured membranes, as this confers additional reduction in postoperative infections beyond cephalosporin alone. 1
The FDA-approved dosing for cefazolin for perioperative prophylaxis is 1 gram IV administered 1/2 hour to 1 hour prior to the start of surgery. 2
Important Clinical Considerations
Timing is critical for tissue penetration: The 30-60 minute window ensures therapeutic antibiotic concentrations are achieved in maternal tissues before bacterial contamination occurs during surgery. 1, 3
Single dose is typically sufficient: No additional doses are recommended for standard cesarean sections, though lengthy procedures (>3 hours) or significant blood loss (>1500 mL) may warrant redosing 3-4 hours after the initial dose. 3
Common Pitfall to Avoid
Do not delay antibiotic administration until after cord clamping in the setting of PPROM—this outdated practice increases maternal infection risk without providing fetal benefit. 1 The evidence clearly supports pre-incision administration for optimal maternal outcomes, which is the priority in this clinical scenario. 1, 3