Rates and success rates of trial of labor after cesarean delivery in the United States, 1990-2009.

This study compares rates of trial of labor after Cesarean delivery (TOLAC) and rates of successful TOLAC between 1990 and 2009. Serial cross-sectional analyses were performed using the National Hospital Discharge Survey data to compare rates of TOLAC and TOLAC success between 1990 and 2009. Joinpoint regression was used to assess trends over time, and logistic regression with marginal effects was used to examine the unadjusted and adjusted significance and magnitude of trends. The rate of TOLAC reached a high of 51.8 % (95 % CI 47.8-55.8 %) in 1995 and a low of 15.9 % (95 % CI 13.8-18.0 %) in 2006, declined, on average, 4.2 (95 % CI -4.8 to -3.9) percentage points per year between 1996 and 2005. Rates increased significantly from 1990 to 1996 and 2005 to 2009. TOLAC success was at its highest rate in 2000, 69.8 % (95 % CI 65.2-74.3 %) and its lowest in 2008, 38.5 % (95 % CI 28.1-48.8 %). The rate of TOLAC success increased significantly between 1990 and 2000, but declined thereafter an average of 3.4 % points per year (95 % CI -4.3 to -2.5). The rate of TOLAC in the US decreased between 1996 and 2005 and the rate of successful TOLAC has declined from 2000 to 2009.