The Study Of The Second Stage Of Labor And Pregnancy Outcomes Without Epidural Analgesia

Objective:To explore the relationship between the length of the second stage of labor without epidural analgesia in Chinese population and pregnancy outcomes to provide a scientific basis for establishing second-stage labor management that is suitable for the national condition.Methods:We did a retrospective analysis of 24474 partuients who were delivered without epidural analgesia in The First Affiliated Hospital of Kunming Medical University from January 1,2014 to December 31,2017.Included 12789 cases with complete records were singleton term gestation and vertex presentation.Excluded 11685 cases were multiple pregnancies,premature birth,non-vertex presentation,scarred uterus(including previous cesarean section history and other uterine surgery histories),first stage-labor cesarean section(cesarean section performed before the second-stage)and cases of missing data.The 12789 cases included were divided into nulliparous group(9517 cases)and multiparous group(3272 cases).Each group was sub-grouped into 4 groups by 1-hour intervals according to the duration of the second stage of labor(<1 hour,1-2 hours,2-3 hours and?3 hours groups).Statistical analyzed the duration of the second stage of labor,and explore the independent risk factors for the extension of the second stage of labor and the impact of the length of the second-stage on pregnancy outcomes.Results:1.The total cesarean section rate during this study period was approximately 30%,and the primary cesarean section rate was approximately 16%.Within the total cohort,8750(90.01%)cases of nulliparous without epidural analgesia completed second-stage labor within 2 hours,3246(96.09%)cases of multiparous within 1 hour.2.Maternal age?35 years,gestational age?40 weeks and birth weight?4000g were the independent risk factors for prolonged second stage of labor in nulliparous and multiparous women.PROM and use of oxytocin were also independent risk factors for the extension of the second stage in nulliparous.3.1 Regardless of parity,prolonged the second stage of labor by 1 hour didn't reduce the second-stage cesarean section rate significantly(OR:0.50,95%CI:0.24-1.07,P=0.073 in nulliparous women).Forceps assisted vaginal delivery had a strong positive correlation with the duration of the second-stage labor.When the second-stage labor exceeded 1 hour,the rate of forceps assisted vaginal delivery increased significantly in nulliparous(OR:2.72,95%CI:1.23-6.01,P<0.05)and multiparous(OR:3.01,95%CI:1.63-5.56,P<0.05).3.2 In terms of pregnancy outcomes,the risk of postpartum hemorrhage and episiotomy had a strong positive correlation with the duration of the second stage of labor in nulliparous and multiparous.When the second-stage labor exceeded 1 hour,the risk of postpartum hemorrhage(OR:1.15,95%CI:1.04-1.28,P<0.05)and episiotomy(OR:2.00,95%CI:1.83-2.18,P<0.05)increased significantly in nulliparous women;the risk of transfusions(OR:4.97,95%CI:1.32-18.73,P<0.05)and episiotomy(OR:7.26,95%CI:4.83-10.90,P<0.05)increased significantly in multiparous women.When the second-stage labor exceeded 2 hours,the risk of postpartum hemorrhage(OR:1.28,95%CI:1.10-1.50,P<0.05)and 3-4 degree laceration(OR:2.21,95%CI:1.20-4.07,P<0.05)increased significantly in nulliparous women;the risk of postpartum hemorrhage(OR:3.14,95%CI:1.21-8.11,P<0.05)increased significantly in multiparous women.After the second stage of labor more than 3 hours,the rate of episiotomy increased significantly in nulliparous women(OR:2.07,95%CI:1.34-3.20,P<0.05).3.3 In terms of neonatal outcomes,although there was no significant correlation between the Apgar score@5 minutes<7 and the duration of the second-stage,the risk of umbilical artery cord PH<7.15 and transmission to NICU for treatment significantly positively correlated with the length of the second stage of labor in nulliparous group.When the second-stage labor exceeded 1 hour,the risk of umbilical artery cord PH<7.15 increased significantly(OR:1.25,95%CI:1.08-1.44,P<0.05).In multiparous group,umbilical artery cord PH<7.15 had no significant correlation with the duration of the second stage of labor.Conclusion:1.Without epidural analgesia,95%of nulliparous completed the second-stage labor within 2.38 hours,which was between Friedman's partograph(2h)and Zhang's partograph(2.8h).95%of multiparous completed the second-stage within 0.87h,which was close to Friedman's partograph(lh).2.Maternal age?35 years,gestational age?40 weeks and birth weight?4000g were the independent risk factors for prolonged second stage of labor in nulliparous and multiparous women.PROM and use of oxytocin were also independent risk factors for the extension of the second stage in nulliparous3.Extending the second-stage by 1 hour based on the Friedman's partograph did not reduce second-stage cesarean delivery rate,but significantly increased the risk of postpartum hemorrhage,blood transfusion,vaginal delivery with forceps,3-4 degree laceration and neonatal umbilical artery cord pH<7.15.The impact of the ACOG's recommendation to extend the second-stage by 1 hour(based on the Friedman's partograph)on pregnancy outcomes in Chinese population needs further study.