Impact of Antibiotic Timing and Hospital Setting on Postoperative Wound Complications in Cesarean Sections

• DOI: 10.54053/001c.133218
• Publication Date: 2025-04-22T15:59:08Z
• Authors: Jaimi Elliott; Gary Menefee; Kathryn Self; Dani Zoorob

The American College of Obstetricians and Gynecologists (ACOG) recommends prophylactic antibiotics within 60 minutes of the start of a cesarean section (CS) or as soon as possible in emergencies to decrease postoperative infections, as per Practice Bulletin 199. Most institutions standardize a 2g preoperative dose of cefazolin for all CS patients. However, the optimal timing within this 60-minute window and the impact of variations in antibiotic administration based on hospital setting (rural vs. urban) remain unclear. This study aimed to analyze the impact of variable antibiotic administration timing for CS on wound complications rates. A secondary objective was to assess whether the hospital setting, rural or urban, influenced the risk of complications based on administration timing. Methodology: A retrospective chart review was conducted on all CS performed between January 1, 2020, and December 31, 2020, at two safety-net hospitals within one large university-based healthcare system in Louisiana—one rural and one urban. Patients with postoperative wound complications identified within 6 weeks postpartum were matched with two control cases based on BMI for each case with wound complications or infection within the same period. Antibiotic administration times were categorized into four groups: >60 minutes before incision, 30-59 minutes before, 0-29 minutes before, and after incision. Demographic factors, including ethnicity, BMI, and diabetic status, as well as antibiotic types, timing, and delivery details, were recorded for each subject. Results: The mean age of patients in the wound complication group was 27 years (SD 5.6), with a mean gestational age of 38 weeks (SD 3.4) and a mean BMI of 41 (SD 10.5). The control group had a mean age of 27.5 years (SD 5.4), gestational age of 38+1 weeks (SD 2.8), and BMI of 40 (SD 9.9), with no statistically significant demographic differences between the groups. The mean antibiotic administration time was 36 minutes before incision (SD 60, CI 23-51) in the wound complication group and 34 minutes before incision (SD 51, CI 24-42) in the control group. The overall infection rate was 7%, with 5.47% at the urban site and 11.07% at the rural site. Stratification by antibiotic timing suggested a linear correlation between too-early antibiotic administration and increased wound infections, with the >60 minutes prior-to-incision group experiencing up to a 37% increase in wound infections. This effect was more pronounced in the rural hospital compared to the urban hospital. Patients receiving nonstandard antibiotic regimens (excluding cefazolin or cefazolin with azithromycin) had significantly higher infection rates (+42%), a trend observed in diabetic and non-diabetic patients. Additionally, patients with abnormal 1-hour glucose tolerance test (GTT) results who had not completed a 3-hour GTT by delivery or who presented with unknown diabetic status had a significantly increased risk of infections, reaching fourfold (4x) when treated with nonstandard regimens. Conclusion: The study findings support ACOG’s recommendation of cefazolin administration within a maximum of 60 minutes before incision, confirming increased wound complication risks with administration times exceeding this window. No significant differences were observed based on shorter administration durations prior to CS, ethnicity, or diabetic status; however, potentially diabetic patients lacking glucose management exhibited higher infection rates. The study highlights the importance of timely antibiotic administration and the need for standardization of antibiotics, particularly in rural settings