Uterine rupture during induced trial of labor among women with previous cesarean delivery

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.