The pattern of labor preceding uterine rupture

Objective: We sought to characterize the labor of women attempting trial of labor after cesarean (TOLAC) who experience uterine rupture. Study Design: We conducted a secondary analysis of a nested case-control study of women attempting TOLAC. Women experiencing uterine rupture (cases) were compared to 2 reference groups: successful TOLAC and failed TOLAC. Interval-censored regression was used to estimate the median time to progress 1 cm in dilation and the total time from 4-10 cm. Results: A total of 115 cases were compared to 341 successful TOLAC and 120 failed TOLAC. The time to progress 1 cm was similar between groups until 7-cm dilation. After 7 cm, cases of uterine rupture required longer to progress than successful TOLAC (median [95th percentile] time from 7-8 cm: 0.38 [1.91] vs 0.16 [0.79] hours; from 8-9 cm: 0.28 [1.10] vs 0.10 [0.39] hours). Women with a uterine rupture had labor curves similar to those with a failed TOLAC. Conclusion: Women with labor dystocia in the active phase of labor should be closely monitored for uterine rupture in TOLAC.