Risk factors for symptomatic uterine rupture during a trial of labor: the 1990s

The purpose of this study is to identify pregnancy and labor factors that place women at increased risk for symptomatic uterine rupture during trial of labor following cesarean section. The study population consisted of 16 women with uterine rupture after a trial of labor who were compared with 32 women without uterine rupture after a trial of labor. Using a case-control study design with a 1:2 match, we examined risk factors that might be associated with an increased risk of uterine rupture. Cases were more likely to have an induction of labor with the use of oxytocin and/or amniotomy (56 vs. 34%) and more likely to undergo augmentation with oxytocin (25 vs. 19%) in comparison with controls. In addition, cases were more likely to be given oxytocin (for either induction or augmentation) (75 vs. 50%) and cervical ripening agents (31 vs. 9%) versus controls. Neonates born after uterine rupture had a higher rate of significant acidosis (pH < 7.0, 57 vs. 0%, p = 0.0002) and lower Apgar scores. There was a significantly higher risk of maternal infection (36 vs. 3%, p = 0.003), transfusion (13 vs. 0%, p = 0.03), and longer length of stay in patients with uterine rupture. There is a trend for increased use of augmentation and induction agents to be associated with uterine rupture. Serious maternal and fetal morbidities are increased following uterine rupture.