Predicting uterine rupture in women undergoing trial of labor after prior cesarean delivery.

Uterine rupture is the most serious complication for women undergoing trial of labor (TOL) after prior cesarean delivery. While rates of uterine rupture vary significantly according to a variety of clinically associated risk factors, the absolute risk for this complication ranges between 0.5 and 4 percent. Previous vaginal delivery and prior successful vaginal birth after cesarean delivery confer the lowest risk of rupture on women attempting TOL. In contrast, multiple prior cesareans, short interpregnancy interval, single layer uterine closure, prior preterm cesarean, labor induction and augmentation have all been suggested in some studies as factors which may increase the rate of uterine rupture. While considering these risk factors is important in counseling women regarding childbirth following cesarean delivery, the infrequency of uterine rupture coupled with relatively weak associations for most risk factors has prevented the development of an accurate prediction tool for uterine rupture. Preliminary studies suggest that sonographic evaluation of the uterine scar may hold some promise for identifying women at risk.