Uterine rupture: Differences between a scarred and an unscarred uterus

Objectives This study aimed to compare risk factors, site of rupture, and outcome of uterine rupture among patients with a scarred versus an unscarred uterus. Study design We conducted a comparison between all cases of uterine rupture (n=53) in women with a scarred versus an unscarred uterus, occurring between January 1988 and July 2002. Results During the study period, there were ruptures among 26 patients with a scarred uterus and 27 patients without a uterine scar. No significant differences were noted between the scarred and unscarred groups while comparing risk factors such as birth order, birth weight, hydramnios, oxytocin induction, diabetes, and malpresentation. The main site of involvement in both groups was the lower uterine segment representing 92.6% of the ruptures in the unscarred group and 92.3% of the ruptures in the scarred uterus group. Cervical involvement was significantly more common among patients without a previous uterine scar (33.3% vs 7.7%; odds ratio [OR]=6.0, 95% CI, 1.16-31.23, P=.04). Conversely, uterus corpus involvement did not differ between the groups. Perinatal mortality did not differ between the groups. In addition, no significant differences were noted regarding maternal morbidity such as the need for hysterectomy, blood transfusion, or length of hospitalization. Conclusion Although cervical involvement was significantly more prevalent in the rupture of an unscarred uterus, no significant differences in maternal or perinatal morbidity were noted between rupture of a scarred versus an unscarred uterus.