Risk Factors Associated with Uterine Rupture and Dehiscence: A Cross-Sectional Canadian Study.

Objective:  To compare maternal and perinatal risk factors associated with complete uterine rupture and uterine dehiscence.

Methods:  Cross-sectional study of patients with uterine rupture/dehiscence from January 1998 to December 2017 (30 years) admitted at the Labor and Delivery Unit of a tertiary teaching hospital in Canada.

Results:  There were 174 (0.1%) cases of uterine disruption (29 ruptures and 145 cases of dehiscence) out of 169,356 deliveries. There were associations between dehiscence and multiparity (odds ratio [OR]: 3.2;  = 0.02), elevated maternal body mass index (BMI; OR: 3.4;  = 0.02), attempt of vaginal birth after a cesarian section (OR: 2.9;  = 0.05) and 5-minute low Apgar score (OR: 5.9;  < 0.001). Uterine rupture was associated with preterm deliveries (36.5 ± 4.9 versus 38.2 ± 2.9;  = 0.006), postpartum hemorrhage (OR: 13.9;  < 0.001), hysterectomy (OR: 23.0;  = 0.002), and stillbirth (OR: 8.2;  < 0.001). There were no associations between uterine rupture and maternal age, gestational age, onset of labor, spontaneous or artificial rupture of membranes, use of oxytocin, type of uterine incision, and birthweight.

Conclusion:  This large cohort demonstrated that there are different risk factors associated with either uterine rupture or dehiscence. Uterine rupture still represents a great threat to fetal-maternal health and, differently from the common belief, uterine dehiscence can also compromise perinatal outcomes.