Comparison of bactericidal properties of alcohol-based chlorhexidine versus povidone-iodine prior to amniocentesis.

OBJECTIVE: To compare the bactericidal properties of povidone-iodine versus alcohol-based chlorhexidine solution for cleansing the gravid abdomen prior to amniocentesis.

METHODS: Fifty study participants were recruited from the University of Texas Women's Clinic in Houston, Texas. Two baseline swabs of the patients' abdomens were obtained to assess bacterial flora prior to treatment. A 10% povidone-iodine solution and 2% chlorhexidine gluconate with 70% isopropyl alcohol solution in a 3-mL prefilled applicator (Chloraprep, Cardinal Health, Inc., Leawood, KS) were then applied on different sides of the abdomen. After 30 seconds, cultures were obtained and plated on Trypticase Soy (PML Microbiologicals, Durham, NC) with sheep's blood agar for aerobic flora. Plates were incubated at 37°C for 48 hours for aerobic flora. Colony-forming units were counted and recorded.

RESULTS: No statistically significant difference was detected between baseline colony counts between the left and right side of each patient's abdomen (p = 0.33) prior to cleansing. Postcleansing colony counts were evaluated, and a statistically significant difference was identified, favoring chlorhexidine as a more efficacious abdominal cleanser (p <0.001).

CONCLUSION: We demonstrated that 2% chlorhexidine with 70% isopropyl alcohol had excellent bactericidal efficacy and was superior to povidone-iodine for cleansing the maternal abdomen.