剖宫产术后阴道分娩的产时影响因素分析

目的:探讨产时因素对剖宫产术后阴道分娩(VBAC)的影响。方法:回顾性分析2016年1月—2021年11月于河北医科大学第四医院进行剖宫产术后再次妊娠阴道试产(TOLAC)的孕妇资料,纳入病例均为单次剖宫产后首次阴道试产的孕妇,统计的病历资料包括孕妇年龄、临产时胎头位置、潜伏期时长、产程中是否催产素加强宫缩、活跃期起始阶段(宫口开大4~5 cm)胎头位置及胎方位。采用单因素分析和多因素Logistic回归分析TOLAC成功的产时影响因素。结果:①纳入行TOLAC的孕妇319例,其中236例成功阴道分娩,VBAC率为74.0%。②单因素分析结果显示,活跃期起始(宫口开大4~5 cm)胎头位于坐骨棘水平及以下(85.3%vs.59.9%,OR=3.895,95%CI:2.282~6.647)、胎方位为枕前位(83.6%vs.62.8%,OR=3.020,95%CI:1.787~5.104)的孕妇TOLAC成功率较高;而产程中需催产素加强宫缩的孕妇TOLAC成功率较低(61.2%vs.77.4%,OR=0.461,95%CI:0.260~0.818)。不同的孕妇年龄、临产时胎头位置、潜伏期时长者TOLAC成功率差异无统计学意义(均P>0.05)。③多因素分析结果显示,产程中需催产素加强宫缩(OR=0.502,95%CI:0.267~0.943)、活跃期起始(宫口开大4~5 cm)胎头位于坐骨棘水平及以下(OR=3.467,95%CI:1.990~6.042)、胎方位为枕前位(OR=2.633,95%CI:1.515~4.575)是VBAC的独立影响因素。结论:对于TOLAC,当产程进展至活跃期起始阶段、胎头仍位于坐骨棘水平以上、胎方位为枕横/后位,或产程中使用催产素加强宫缩者,应严密监测母胎情况及产程进展。必要时放宽指征及时行剖宫产,以保障母胎安全。

Intrapartum Factors Influencing Vaginal Birth after Cesarean

Objective: To investigate the postpartum factors of vaginal birth after cesarean(VBAC). Methods: From January 2016 to November 2021, the pregnant women who underwent the trial of labor after cesarean section (TOLAC) in The Fourth Affiliated Hospital of Hebei Medical University were retrospectively analyzed. All included cases were the first vaginal delivery after a single cesarean section. The medical records included: maternal age, fetal head position during labor, latent period, whether use oxytocin to strengthen contractions during labor, fetal head position during active period (4-5 cm), and fetal position. The influencing factors of VBAC were analyzed by the univariate and multivariate logistic regression. Results: ①There were 319 pregnant women tried vaginal delivery, of which 236 had a final vaginal delivery, with a VBAC rate of 74.0%. ②The univariate analysis showed that the fetal head in the active phase (4-5 cm) was located at the level of the ischial spine or below (85.3% vs. 59.9%, OR=3.895, 95%CI: 2.282-6.647), and the fetal position is anterior occipital (83.6% vs. 62.8%, OR=3.020, 95%CI: 1.787-5.104) had higher successful rate of TOLAC. The success rate of TOLAC was lower in women who needed oxytocin strengthens contractions during labor (61.2% vs. 77.4%, OR=0.461, 95%CI: 0.260-0.818). There were no significant differences in the maternal age, fetal head position at delivery and latent period between the two groups (P>0.05). ③Multivariate analysis showed that oxytocin use during labor (OR=0.502, 95%CI: 0.267-0.943), fetal head at or below the level of ischial spine during active phase (OR=3.467, 95%CI: 1.990-6.042), fetal position at the anterior occipital (OR=2.633, 95%CI: 1.515-4.575) were independent influencing factors of VBAC. Conclusions: For pregnant women who underwent TOLAC, the maternal and fetal situation and labor progress should be closely monitored when the labor progresses to the beginning of active phase, the fetal head is still above the level of ischial spine, and fetal position is occipital/posterior, or oxytocin is used to strengthen the contractions during labor. If necessary, the surgical indications for cesarean section should be relaxed to ensure the safety of maternal and fetal.