The national primary cesarean delivery rate increased until 2004, but after 2004, this rate cannot be tracked using Vital Statistics data. Additionally, it is unknown whether changes in the primary cesarean delivery rate reflect changes in the rate of labor attempts, labor success, or both. Here, using hospital discharge data, we examined national trends in primary cesarean deliveries, labor attempts, and labor success among women without prior cesarean delivery between 1990 and 2010.

This analysis of serial cross-sectional data from the National Hospital Discharge Survey used Joinpoint regression to assess trends over time and logistic regression with marginal effects to identify rates of change over time and adjust for demographic and clinical factors.

The primary cesarean delivery rate declined 0.2 percentage points per year (95% confidence interval [CI], 0.1–0.3) between 1990 and 1999, increased 1.0 percentage point per year (95% CI, 0.8–1.2) between 1999 and 2004, and increased 0.3 percentage points (95% CI, 0.1–0.6) per year from 2004 until 2010. Between 1998 and 2005, the rate of labor attempts declined 0.4 percentage points (95% CI, 0.3–0.5) per year. No changes in the labor attempt rate occurred between 2005 and 2010. Labor success rates increased 0.2 percentage points (95% CI, 0.1–0.3) per year between 1990 and 1998 but then declined 0.5 (95% CI, 0.5–0.8) percentage points per year from 1998 to 2010. Adjusted results were similar.

The primary cesarean delivery rate continued to increase after 2004. Increases in the primary cesarean delivery rate after 2005 were driven by declines in labor success rates.