A 10-year population-based study of uterine rupture

To review the incidence, associated factors, methods of diagnosis, and maternal and perinatal morbidity and mortality associated with uterine rupture in one Canadian province.

Using a perinatal database, all cases of uterine rupture in the province of Nova Scotia for the 10-year period 1988-1997 were identified and the maternal and perinatal mortality and morbidity reviewed in detail.

Over the 10 years, there were 114,933 deliveries with 39 cases of uterine rupture: 18 complete and 21 incomplete (dehiscence). Thirty-six women had a previous cesarean delivery: 33 low transverse, two classic, one low vertical. Of the 114,933 deliveries, 11,585 (10%) were in women with a previous cesarean delivery. Uterine rupture in those undergoing a trial for vaginal delivery (4516) was complete rupture in 2.4 per 1000 and dehiscence in 2.4 per 1000. There were no maternal deaths, and maternal morbidity was low in patients with dehiscence. In comparison, 44% of those with complete uterine rupture received blood transfusion (odds ratio 7.60, 95% confidence interval 1.14, 82.14, P =.025). Two perinatal deaths were attributable to complete uterine rupture, one after previous cesarean delivery. Compared with dehiscence, infants born after uterine rupture had significantly lower 5-minute Apgar scores (P <.001) and asphyxia, needing ventilation for more than 1 minute (P <.01).

In 92% of cases, uterine rupture was associated with previous cesarean delivery. Uterine dehiscence was associated with minimal maternal and perinatal morbidity. In contrast, complete uterine rupture was associated with significantly more maternal blood transfusion and neonatal asphyxia.