| ObjectiveTo study the labor characteristics of parturients who successfully gave vaginal birth after one cesarean(VBAC).MethodsData were from a retrospective study that abstracted detailed labor and delivery information from electronic medical records in the Maternal and Child Care Service Center of Fujian Province from January 1st 2015 to December 31st 2017.A total of 657parturients were selected who had a singleton term gestation,spontaneous onset of labor,vertex presentation,Vaginal birth after one cesarean,and a normal perinatal outcome.Divided the samples into 2 groups:a total of 170 parturients was trial of labor group in last pregnancy had and a total of 487 parturients was no trial of labor group in last pregnancy by the indications for cesarean section.Analyzed the duration and characteristics of the labor of all the objects.Compared the duration of labor and labor characteristics of different groups.Used multinomial model to repeated-measures analysis and depicted the average labor curves.To estimate duration of labor,used the regression analysis of interval-censored data,to estimate the distribution of times for progression from one integer centimeter of dilation to the next,and depicted the 95th percentiles of cumulative duration of labor.SAS 9.2 system was applied for independent-sample T test,paired sample T test,Mann-Whitney test andχ~2 test.Results1.The labor characteristics of VBAC(1)The 95th percentiles of cumulative duration of first stage of labor,second stage of labor,total stage of labor was 12.67h,1.18h,13.30h.(2)Compared with Zhang’s study,the cervical dilation rate of VBAC was faster,but the cervical dilation rate of VBAC was similar to women of parity 1 to progress from8cm to 10 cm of dilation and the second stage of labor.(3)No deceleration was observed in the labor average curve.The slope of the average curve was lower at cervical dilation of 4cm or less,it increased gradually after cervical dilation of 4cm to 6cm.(4)Progress to 4cm,5cm and 6cm of dilation,the samples in active phase took an accumulative proportion at 58.0%,78.2%and 96.6%respectively.2.Comparison between the labor characteristics of two groups(1)The average curve trend of the two groups was consistent.The slope of the average curve of the trial of group began to accelerate earlier than the no trial of group.(2)Compared the rate of cervical dilation,there was no statistically significant difference between the two groups at 3~6cm(P<0.05),the rate of cervical dilation of the vaginal trial group was greater than that of the no trial group at 6~10cm,and the difference was statistically significant(P<0.05).(3)Labor of the trial of labor group and of no trial of labor group may take over 1.81h vs 2.63h;0.74h vs 2.07h;0.56h vs 1.27h;0.46h vs 1.26h to progress from 6cm to 7cm,7cm to 8cm,8cm to 9cm,9cm to 10cm of dilation.(4)The 95th percentiles of cumulative duration of the second stage of labor was about1.0h regardless of the case group or the control group.Conclusions1.The rate of cerviacal dilation accelerated of VBAC was faster than previously described.Obstetric practice standards based on data generated from previously studies may not be appropriate for TOLAC parturients.2.The onset of the active phase of TOLAC and of parturients have no cesarean section were the same.3.Labor management of TOLAC should be treated differently according to whether had any trial of labor.The time interval for evaluation of the progress of the labor should be shortened if parturients were trial of labor in the last pregnancy.4.The second stage of labor management of TOLAC should not be treated differently whether had any trial of labor. |
