Objective: This study was undertaken to compare the rates of uterine rupture during induced trials of labor after previous cesarean delivery with the rates during a spontaneous trial of labor.
Study design: All deliveries between 1992 and 1998 among women with previous cesarean delivery were evaluated. Rates of uterine rupture were determined for spontaneous labor and different methods of induction.
Results: Of 2119 trials of labor, 575 (27%) were induced. The overall rate of uterine rupture was 0.71% (15/2119). The uterine rupture rate with induced trial of labor (8/575; 1.4%) was significantly higher than with a spontaneous trial of labor (7/1544; 0.45%; P =.0004). Uterine rupture rates associated with different methods of induction were compared with the rate seen with spontaneous labor and were as follows: prostaglandin E(2) gel, 2.9% (5/172; P =.004); intracervical Foley catheter, 0.76% (1/129; P =.47); and labor induction not requiring cervical ripening, 0.74% (2/274; P =.63). The uterine rupture rate associated with inductions other than with prostaglandin E(2) was 0.74% (3/474; P =.38). The relative risk of uterine rupture with prostaglandin E(2) use versus spontaneous trial of labor was 6.41 (95% confidence interval, 2. 06-19.98).
Conclusion: Induction of labor was associated with an increased risk of uterine rupture among women with a previous cesarean delivery, and this association was highest when prostaglandin E(2) gel was used.