Primary Hypothesis: chlorhexidine gluconate alcohol skin antiseptic preparation is superior to povidone-iodine scrub and paint skin antiseptic preparation for prevention of cesarean related surgical site infection.

Patients who are considered likely to need cesarean delivery or who are planning cesarean will be recruited and consented for study participation during prenatal care and/or at time of admission to labor and delivery.

Patients undergoing cesarean who meet inclusion/exclusion criteria will be randomized to one of two surgical preparations as listed above (1. Chlorhexidine Gluconate (CHG)-alcohol, or 2. Povidone Iodine (P-I) scrub and paint. Randomization will be performed by the consenting surgeon (listed as key personnel) after the patient has arrived into the operating room for cesarean. Pre-operative surgical site antisepsis will be performed according to randomization. All other surgical practices will remain at the surgeon's discretion according to standard of care at Metrohealth.

Patients will be examined daily by the obstetric team and evaluated for signs and symptoms of surgical site infection, as standard in the investigators institution. The chart will be reviewed to determine if the patient was diagnosed during admission, or, re-admitted because of surgical site infection. The patient will also be questioned regarding any treatment or diagnosis of Surgical Site Infection (SSI) that occured after discharge to home at the routine six week post-operative visit. If patient does not return for the routine post-operative visit, the investigator will attempt to contact the patient by telephone to determine if the patient had been diagnosed or treated for surgical site infection. If patient is lost to 6 week follow up, subanalysis will be performed on available data derived from hospitalization and hospital Electronic Medical Record (EMR).

Data will be captured in RedCAP database.

Additional data will be captured that may affect patient likelihood of surgical site infection to ensure that both groups are statistically equal in risk factors for SSI: labor or rupture of membranes prior to cesarean, maternal age, estimated gestational age, Body Mass Index (BMI), gravity, parity, race, smoking status, hypertensive morbidity, diabetes, estimated blood loss, operative time, race, insurance type, general versus regional anesthesia, appropriate antibiotic prophylaxis given, skin closure (sutures v. staples).

Power analysis was performed: assuming 7.5% risk of cesarean site infection and a 50% reduction with chlorhexidine, 932 individuals will be recruited. Approximately 800 cesareans are performed at the investigators institution per year and the investigators anticipate that 80% will be eligible to participate.

Data review will be done every 6 months or every 200 patients and analyzed, whichever is sooner. Analysis will be performed by the Primary Investigators (PI) for completeness, accuracy, strict adherence to study protocol, safety, and statistical significance. The investigators site is also subject to periodic audits by the investigators Institutional Review Board (IRB).

Inclusion Criteria:

• cesarean delivery
• age 18-65
• ability to consent in English or Spanish

Exclusion Criteria:

• inability or unwillingness to consent to study participation in English or Spanish
• current incarceration
• pre-operative diagnosis of chorioamnionitis
• perceived inability to complete follow up for data collection
• any prior known allergy or adverse reaction to either study preparation

4 weeks

Adverse event data was collected at the same time as primary outcome data.

Lack of masking of clinical personnel to treatment assignment.