Maternal - fetal outcomes and risk factors of uterine rupture in the setting of pregnant women with scarred versus unscarred uterus: a systematic review and meta - analysis

This study aimed to compare risk factors and outcomes of uterine rupture among patients with a scarred versus an unscarred uterus. In this meta - analysis, we analyzed studies published in PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), International Clinical Trials Registry Platform (ICTRP), and Clinical Trials. gov that appeared in our search from inception to 18/03/2024. This study included a total of 15 studies (1 prospective study and 14 retrospective studies). It comprised 914 cases of patients with scarred uterus and 468 cases of patients with unscarred uterus. Among the 914 scarred uterus cases, 861 (94.2%) were due to prior cesarean section, and the remaining 53 (5.8%) were attributable to other uterine surgeries. The meta - analysis demonstrated that the rates of perinatal mortality, hysterectomy, and postpartum hemorrhage were higher in women with unscarred uterine rupture than in scarred group. Although maternal mortality was also elevated in the unscarred group, the difference did not reach statistical significance. Additionally, compared with scarred uterine rupture, cases of unscarred uterine rupture were more frequently associated with advanced maternal age, oxytocin use, induction of labor, and malpresentation. Compared to patients with scarred uterine rupture, unscarred uterine rupture is associated with significantly higher risks of perinatal mortality, hysterectomy, and postpartum hemorrhage. Additionally, advanced maternal age, a higher incidence of oxytocin, induction of labor, and malpresentation were associated with rupture in the unscarred uterus group. These factors should be taken seriously. Early identification of relevant risk factors is crucial to avoid potential obstetric emergencies, prevent diagnostic delays, and allow timely surgical intervention to improve maternal and neonatal outcomes.