Association of Montevideo units with uterine rupture in women undergoing a trial of labor.

Objective: To determine if an association exists between Montevideo units (MVUs) and uterine rupture in women undergoing trial of labor after cesarean (TOLAC).

Study Design: A case-control study of women who underwent a TOLAC, comparing uterine rupture (n = 9) to successful vaginal birth after cesarean (VBAC) (n = 48) and failed TOLAC (n = 35). MVUs were calculated in 12 10-minute intervals prior to uterine rupture, cesarean delivery, or complete dilation in the VBAC group.