Maternal lower urinary tract injury at the time of Cesarean delivery

Introduction and hypothesis To determine the incidence of lower urinary tract (LUT) injury at the time of Cesarean delivery (CD) and to identify factors associated with LUT injury. Methods Cases of LUT injury at delivery between 2001 and 2012, were identified by ICD-9 code. Chart review was utilized for verification and descriptive data collection. LUT injury incidence rates were calculated using annual delivery totals and trends over time were calculated using simple linear regression. LUT injury was classified as full-thickness bladder injury (including ureteral injury) or partial-thickness bladder injury based on degree of injury and post-operative intervention. Each case was year-matched to generate two CD controls. Logistic regression analysis was performed using maternal, delivery, and health system characteristics to identify factors associated with full or partial injury. Appropriate statistical analyses were performed with significance at p<0.05. Results Overall delivery and CD rates increased during the study time period, but despite the increase in CD rates, annual rates of LUT injury did not vary significantly (p=0.658). Of the 72 LUT injuries reported, 39 (54 %) were full-thickness bladder, 2 (3%) ureteral, and 31 (43 %) were partial-thickness bladder injuries. Full injury, controlling for repeat CD, was associated with increasing maternal age, transfusion, and active second stage of labor. Partial injury, was associated with increasing maternal age and delivery in the first half of the academic year. Conclusions Despite an increasing volume of CDs, LUT injury remained relatively uncommon (0.3% of all CDs). Full and partial bladder injuries have unique risk profiles.