Timing of Preoperative Antibiotic Administration for Cesarean Section in PPROM
Administer intravenous antibiotics within 60 minutes before the cesarean delivery skin incision (Answer: B - 60 minutes before incision).
Recommended Timing Window
The Enhanced Recovery After Surgery (ERAS) Society guidelines provide a strong recommendation (high-quality evidence) that intravenous antibiotics should be administered routinely within 60 minutes before the cesarean delivery skin incision in all women undergoing cesarean section, including those with PPROM. 1
The American College of Obstetricians and Gynecologists (ACOG) supports administration 30-60 minutes prior to the start of surgery, as this timing ensures therapeutic antibiotic concentrations are achieved in maternal tissues before bacterial contamination occurs during surgery. 2
The FDA-approved cefazolin label specifies administration 1/2 hour to 1 hour (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. 3
Why This Timing Matters in PPROM
PPROM represents a higher-risk scenario, classified as a clean-contaminated (class II) or potentially contaminated (class III) incision, carrying increased risk from both skin flora and vaginal flora exposure. 2
The 30-60 minute window ensures therapeutic antibiotic concentrations are achieved in maternal tissues before bacterial contamination occurs during surgery, reducing the risk of postoperative infections in women with PPROM. 2, 4
Historical practice has shifted from administering antibiotics after cord clamping to pre-incision administration, as current evidence demonstrates that pre-incision administration decreases wound infections without causing fetal harm. 2
Recommended Antibiotic Regimen for PPROM
First-generation cephalosporin (cefazolin) is recommended as the primary choice for all women undergoing cesarean section, including those with PPROM. 1, 2
The addition of azithromycin is strongly recommended in women in labor or with ruptured membranes, as this confers additional reduction in postoperative infections beyond cephalosporin alone. 1, 2, 4
This combination addresses both the immediate surgical prophylaxis needs and the polymicrobial nature of infection risk in PPROM. 1
Critical Pitfall to Avoid
Do not delay antibiotic administration until after cord clamping in the setting of PPROM, as this outdated practice increases maternal infection risk without providing fetal benefit. 2
Administering antibiotics too early (>60 minutes before incision) may result in subtherapeutic tissue levels at the time of incision, while administering too late increases infection risk. 3
Distinction from Latency Antibiotics
The preoperative antibiotic dose discussed here is separate from the latency antibiotics (7-day course of ampicillin and erythromycin) that should have been administered earlier during expectant management of PPROM to prolong pregnancy and reduce neonatal morbidity. 1, 5, 6
Women with PPROM at ≥24 weeks gestation should receive latency antibiotics (GRADE 1B recommendation), but when proceeding to cesarean section, they still require appropriate surgical prophylaxis within 60 minutes of incision. 1, 5