Preliminary data for 2005 indicate that 30.2% of all live births in the United States were cesarean deliveries,marking the highest U.
S. total cesarean rate ever reported. Since 1996, the total cesarean rate has increased by 46%, or driven by both an increase in the percentage of all women having a first cesarean and a decline in the percentage of women delivering vaginally after a preceding cesarean. Cesarean rates vary considerably among states but tend to be lower in the western mountain states and upper Midwest region and higher in the Southeast and East regions.
Source: cdc.gov