Contemporary epidemiology and novel predictors of uterine rupture: a nationwide population-based study.

PURPOSE: In spite of several policies aiming to decrease cesarean rates and related complications such as uterine rupture, data show that uterine rupture and associated morbidity are increasing along the years. Whether previously unidentified risk factors are currently playing an important role on these trends is unknown. We analyze current risks of uterine rupture and main preceding factors from more recent years compared to former data.

METHODS: All uterine rupture cases in the US from 2011-2012 were selected, with matched non-uterine rupture cases selected as controls. Variables considered for analysis included demographics, maternal morbidity, and obstetric complications. Likelihood forward selection was used to identify main risk factors of uterine rupture. Medians of main factors identified were used to simulate groups at risk and calculate odds ratios of uterine rupture.

RESULTS: From ~8 million births, 1925 presented uterine rupture. In patients with no prior cesarean delivery, multiple gestation, chronic hypertension and chorioamnionitis presented the highest odds of uterine rupture, with the combination of these factors increasing the odds of rupture 59 times (~1%). In women with prior cesarean delivery, induction/augmentation and chorioamnionitis were the most significant predictors, with the combination increasing the odds 33 times (~3%).

CONCLUSIONS: Despite policies implemented and changes in clinical practice, uterine rupture remains an important issue. Previously unidentified risk factors are playing now an important role, information that should be considered during patient counseling and clinical practice. Combinations of some of these factors may increase the risk of uterine rupture significantly enough to modify clinical care.