History of cesarean before 32 weeks’ gestation and trial of labor: What is the risk of uterine rupture?

Objectives. To estimate the risk of uterine rupture in women with a previous cesarean delivery before 32 weeks’ gestation and a trial of labor. Design. Retrospective case control study. Setting. Level III maternity center. Methods. Among women with trial of labor, the case and control groups were women with previous cesarean section before and after 32 weeks, respectively. The main outcome was uterine rupture, defined as rupture of the three layers of the uterine wall. Results. The study compared 108 trials of labor in patients with a previous cesarean delivery at a mean gestation of 29.8 weeks±2.0 SD and 137 trials of labor in patients with a previous cesarean delivery at a mean gestation of 39.2 weeks±2.3 SD. Mode of delivery did not differ between groups. Two uterine ruptures (1.9%, 95% CI: 0.0–4.4) occurred in the case group and none in the control group (p=0.16). Uterine ruptures caused no serious maternal or neonatal complications. The condition of the neonates was similar in the two groups. Conclus...