[Establish and application of scoring scale for trial of labor after cesarean section]

Objective: To establish a scoring scale for trial of labor after cesarean section (TOLAC), to explore the evaluation ability of this scoring scale for vaginal delivery after cesarean section (VBAC), and to improve the success rate of TOLAC. Methods: The delivery information of 661 TOLAC pregnant women admitted to Zhengzhou Central Hospital Affiliated to Zhengzhou University from 2014 to 2017 was retrospectively analyzed, and the TOLAC scoring scale was established by referring to relevant literatures. A prospective cohort study of pregnant women with TOLAC from January 2018 to December 2019 in Zhengzhou Central Hospital was conducted, including 440 pregnant women who were excluded from contraindications in trial labor. According to TOLAC scoring scale, pregnant women were divided into 3 groups, 0-6 group (94 cases), 7-9 group (234 cases) and 10-15 group (112 cases). The success rate of trial labor, failure reasons and incidence of maternal and neonatal complications were compared among the three groups. Results: (1) The overall success rate of TOLAC in 440 pregnant women was 75.0% (330/440). The success rates of 0-6, 7-9 and 10-15 groups were 53.2% (50/94), 76.9% (180/234) and 89.3% (100/112), respectively. The success rate of 10-15 group were significantly higher than those of 0-6 and 7-9 groups (all P<0.05). (2) Among the causes of trial labor failure, there were statistically significant differences between the three groups in terms of threatened uterine rupture and maternal abandonment (all P<0.05). Pairings showed that the incidences of threatened uterine rupture and maternal abandonment in 0-6 group was lower than those in 7-9 and 10-15 groups, and the differences were statistically significant (all P<0.05). (3) Maternal and neonatal complications mainly included postpartum hemorrhage and neonatal asphyxia, but there were no significant difference in the incidence of TOLAC success or failure among the three groups (all P>0.05). There was no uterine rupture in all groups. (4) The main factors affecting TOLAC score of pregnant women in the three groups included natural labor, estimated weight of the fetus at this time, Bishop score of the cervix at admission and gestational age, and the scores of the above indexes in 10-15 group were significantly higher than those in 0-6 group and 7-9 group (all P<0.05). Conclusions: TOLAC scoring scale has more accurate evaluation ability for VBAC, which could improve the success rate of TOLAC and maternal and child safety. The score of 0-6 is not recommended for vaginal trial labor, the score of 7-9 is recommended for vaginal trial labor, and the score of 10-15 is strongly recommended for vaginal trial labor.