Delivery modes and their influencing factors of pregnant women with previous cesarean section: a retrospective study of 474 gravidas

Abstract

Objective To investigate the safety of vaginal delivery in gravidas with previous cesarean section and its influencing factors. Methods Four hundred and seventy-four full-term gravidas who received cesarean section at the Department of Obstetrics and Gynecology of Peking University First Hospital from January 1, 2012 to August 31, 2014 were enrolled in this study. Among those subjects, 38 who underwent successful vaginal delivery were grouped into vaginal birth after cesarean (VBAC) group, and the other 436 accepting repeated cesarean section were grouped into cesarean group. Delivery outcomes and maternal/neonatal complications of the two groups were retrospectively analyzed with two-sample t-test and Chi-square test. Results Among the 45 patients (9.5%) who attempted VBAC, seven underwent cesarean section for suspected fetal distress and the other 38 (84.4%) succeeded in vaginal birth without uterine rupture. The amount of postpartum hemorrhage in patients of cesarean group was more than that of VBAC group [(330.8±94.8) vs (257.7±199.7) ml, t=2.021, P<0.01] after exclusion of three patients with dangerous placenta previa, and the postpartum hospital stay was shorter than that of cesarean group [(2.5±1.4) vs (4.5±1.3) d, t=7.952, P<0.01]. There were three newborns with neonatal asphyxia, twelve with neonatal infections and forty transferred to the Pediatrics Department following cesarean section. Besides, complications of headache and urinary retention occurred in 20 and 32 mothers after cesarean section, respectively. However, no complication occurred in VBAC group. Sixty-three cesarean sections were indicated as thin lower uterine segment and among them, fourteen (22.2%) had muscular rupture. Among the six patients who complained of tenderness in lower uterine segment, three were found having muscular rupture during cesarean section. Conclusion VBAC is an option for gravidas with history of cesarean section only if they meet the criteria for VBAC attempt. VBAC could lower the cesarean section rate without increase the incidence of complications. The rate of trial of labor after cesarean was low, patients education should be strengthened to increase it. Key words: Vaginal birth after cesarean; Trial of labor; Premature rupture of fetal membranes; Natural childbirth