Cesarean section is the most commonly performed surgical procedure in the United States, with nearly 1.3 million cases performed each year. After rising for several decades, the cesarean rate has plateaued at approximately 32% of all deliveries.1 Some portions of the procedure have been thoroughly investigated in the literature, while others have not. The purpose of this article is to review the steps in a cesarean delivery and examine the best available evidence for performing the procedure.
Surgical site infections (SSIs) add significantly to a patient’s cost of care. Cesarean sections are associated with a 10-fold increased risk of infection as compared to vaginal delivery.2 Abdominal preparations with a bactericidal solution have been shown to decrease the risk of a SSI. The preparations come in a variety of types, but the most commonly studied are povidone-iodine (PI), PI-alcohol, and chlorhexidine gluconate (CHG)-alcohol.
In 2012, a Cochrane Review3 found insufficient evidence to recommend one skin preparation over another, but at that time data in obstetrics were lacking. Huang et al4 performed a more recent meta-analysis comparing CHG versus PI preparations, both with and without alcohol, and found no difference in SSI rates. This was supported in a subgroup analysis comparing CHG-alcohol versus PI-alcohol (RR 0.59, CI 0.33-1.06). Individual studies, however, varied in both concentration of the preparation and presence of other agents, such as isopropyl alcohol. They also noted a lack of quality studies.
In 2016, Tuuli et al5 randomized patients undergoing cesarean deliveries to PI-alcohol or CHG-alcohol. There were significantly lower SSI rates in the CHG group (RR = 0.55; CI 0.34-0.90). Unlike prior studies, this study included unscheduled cesarean deliveries (42%), improving the generalizability of the results. In general, CHG-alcohol solutions have been shown to decrease SSI rates in a variety of surgeries; based on these studies and the results of Tuuli’s trial, CHG-alcohol skin preps are a reasonable first choice for obstetrical patients. Of note, alcohol-containing skin preps require 3 minutes of drying time to avoid the flammability that may occur prior to evaporation, whereas preparations without alcohol can be used immediately without a “dry time.” The methods of application are different and the manufacturers’ instructions should be followed for proper application.
Vaginal preparation before cesarean delivery
Vaginal preparation with bactericidal solutions has been studied as a mechanism to reduce infectious morbidity after cesarean delivery. Vaginal cleansing with PI has been shown to significantly reduce incidence of endometritis by over 50%.6 This was even more pronounced for women in labor or with ruptured membranes at the time of cesarean. These findings were supported in a 2017 meta-analysis of studies using either a PI- or CHG-based vaginal prep, which found a reduction in endometritis and postoperative fever with vaginal preparation (RR 0.52, CI 0.28-0.97), even more so in women laboring or with ruptured membranes (RR 0.23, CI 0.10-0.52).7
Whether this translates to benefit in non-laboring or unruptured patients is less clear. Furthermore, many of the studies included in this meta-analysis excluded patients with chorioamnionitis or included patients who received antibiotics after cord clamping, a practice known to increase SSI risk. Lastly, it is unknown how vaginal preparation may impact the vaginal microbiome and infant health. More data from a modern setting—incorporating current skin preparation solutions and antibiotic administration practices—are needed to fully evaluate the potential impact of vaginal cleansing.