Risk factors for bladder injury during cesarean delivery

To identify risk factors for bladder injury during cesarean delivery so as to inform patients and practitioners of these risks.

We conducted a case-control study of women undergoing cesarean delivery at Women and Infants Hospital between January 1995 and December 2002. Cases were women with bladder injuries at the time of cesarean delivery. Two controls per case were selected randomly. Medical records were reviewed for demographic and clinical data to compare cases and controls.

Forty-two bladder injuries were identified among 14,757 cesarean deliveries (incidence of 0.28%). Prior cesarean delivery was more prevalent among cases than controls (67% versus 32%, P < .01). The adjusted risk for bladder injury associated with prior cesarean delivery was 3.82 (95% confidence interval 1.62-8.97). Statistically significant differences (P values < or = .01) between cases and controls were found in emergent timing of delivery (31% versus 11%), labor before cesarean (83% versus 61%), attempted vaginal birth after cesarean (64% versus 22%), concurrent uterine rupture (14% versus 0%), adhesions (60% versus 10%), age (33.6 versus 29.3 years), and body mass index (29.9 versus 33.0 kg/m2). No differences were found among type of uterine incision, labor induction, chorioamnionitis, fetal position, gestational age, or maternal illnesses.

Prior cesarean delivery is a risk factor for bladder injury at the time of repeat cesarean delivery. Patients should be counseled regarding this risk, particularly in the setting of increasing rates of elective primary cesarean delivery.