Abstract：
OBJECTIVE: Obstetric anal sphincter injury (OASI) is a major complication associated with vacuum-assisted vaginal delivery (VAVD). The aim of this study was to evaluate risk factors related to vacuum extraction that are associated with OASI.
METHODS: This was a case-control study performed at a tertiary university teaching hospital. Included were patients aged 18-45 years who had a singleton pregnancy resulting in a live, term, VAVD. The study group consisted of women diagnosed with OASI following vacuum extraction. The control group included women following VAVD without OASI. Matching at a ratio of 1:2 was performed. Groups were compared regarding demographic, obstetric. and labor-related parameters, specifically focusing on variables related to the vacuum procedure itself.
RESULTS: One hundred and ten patients within the study group and 212 within the control group were included in the final analysis. Patients in the OASI group were more likely to undergo induction of labor, use of oxytocin during labor, increased second stage of labor, higher likelihood of the operator being a resident, increased number of pulls, procedure lasting under 10 min, occipito-posterior head position at vacuum initiation, episiotomy, increased neonatal head circumference, and birthweight. Multivariate logistic regression analysis revealed that increased week of gestation (OR 1.67, 95% CI 1.25-2.22, p < 0.001), unsupervised resident performing the procedure (OR 4.63, 95% CI 2.17-9.90), p < 0.001), indication of VAVD being fetal distress (OR 2.72, 95% CI 1.04-7.10, p = 0.041), and length of procedure under 10 min (OR 4.75, 95% CI 1.53-14.68, p = 0.007) were associated with OASI. Increased maternal age was associated with lower risk of OASI (OR 0.9, 95% CI 0.84-0.98, p = 0.012).
CONCLUSIONS: When performing VAVD, increased week of gestation, unsupervised resident performing the procedure, fetal distress as vacuum indication, and vacuum procedure under 10 min were associated with OASI. In contrast, increased maternal age was shown to be a protective factor.
METHODS: This was a case-control study performed at a tertiary university teaching hospital. Included were patients aged 18-45 years who had a singleton pregnancy resulting in a live, term, VAVD. The study group consisted of women diagnosed with OASI following vacuum extraction. The control group included women following VAVD without OASI. Matching at a ratio of 1:2 was performed. Groups were compared regarding demographic, obstetric. and labor-related parameters, specifically focusing on variables related to the vacuum procedure itself.
RESULTS: One hundred and ten patients within the study group and 212 within the control group were included in the final analysis. Patients in the OASI group were more likely to undergo induction of labor, use of oxytocin during labor, increased second stage of labor, higher likelihood of the operator being a resident, increased number of pulls, procedure lasting under 10 min, occipito-posterior head position at vacuum initiation, episiotomy, increased neonatal head circumference, and birthweight. Multivariate logistic regression analysis revealed that increased week of gestation (OR 1.67, 95% CI 1.25-2.22, p < 0.001), unsupervised resident performing the procedure (OR 4.63, 95% CI 2.17-9.90), p < 0.001), indication of VAVD being fetal distress (OR 2.72, 95% CI 1.04-7.10, p = 0.041), and length of procedure under 10 min (OR 4.75, 95% CI 1.53-14.68, p = 0.007) were associated with OASI. Increased maternal age was associated with lower risk of OASI (OR 0.9, 95% CI 0.84-0.98, p = 0.012).
CONCLUSIONS: When performing VAVD, increased week of gestation, unsupervised resident performing the procedure, fetal distress as vacuum indication, and vacuum procedure under 10 min were associated with OASI. In contrast, increased maternal age was shown to be a protective factor.
摘要：
目的：产科肛门括约肌损伤（OASI）是与真空辅助阴道分娩（VAVD）相关的主要并发症。这项研究的目的是评估与OASI相关的与真空提取相关的风险因素。
方法：这是一项在一所大学教学医院进行的病例对照研究。包括18-45岁的单胎妊娠导致活体妊娠的患者，term,VAVD.研究组由在真空提取后诊断为OASI的女性组成。对照组包括VAVD后无OASI的女性。以1:2的比率进行匹配。群体在人口统计方面进行了比较，产科。和劳动力相关的参数，特别关注与真空程序本身相关的变量。
结果：最终分析包括研究组中的110例患者和对照组中的212例患者。OASI组的患者更有可能进行引产，在分娩过程中使用催产素，增加第二阶段的劳动，运营商是居民的可能性更高，拉动次数增加，程序持续10分钟以下，真空启动时枕后头位置，会阴切开术,新生儿头围增加，和出生体重。多因素logistic回归分析显示孕周增加(OR1.67,95%CI1.25-2.22,p<0.001),执行该程序的无监督居民(OR4.63，95%CI2.17-9.90)，p<0.001)，VAVD指征为胎儿宫内窘迫(OR2.72,95%CI1.04-7.10,p=0.041),10分钟以下的手术时间（OR4.75，95％CI1.53-14.68，p=0.007）与OASI相关。母亲年龄增加与OASI风险降低相关(OR0.9,95%CI0.84-0.98,p=0.012)。
结论：执行VAVD时，妊娠周增加，无人监督的居民执行程序，胎儿窘迫作为真空指征，10分钟下的真空程序与OASI相关。相比之下,产妇年龄的增加被证明是一个保护因素.
方法：这是一项在一所大学教学医院进行的病例对照研究。包括18-45岁的单胎妊娠导致活体妊娠的患者，term,VAVD.研究组由在真空提取后诊断为OASI的女性组成。对照组包括VAVD后无OASI的女性。以1:2的比率进行匹配。群体在人口统计方面进行了比较，产科。和劳动力相关的参数，特别关注与真空程序本身相关的变量。
结果：最终分析包括研究组中的110例患者和对照组中的212例患者。OASI组的患者更有可能进行引产，在分娩过程中使用催产素，增加第二阶段的劳动，运营商是居民的可能性更高，拉动次数增加，程序持续10分钟以下，真空启动时枕后头位置，会阴切开术,新生儿头围增加，和出生体重。多因素logistic回归分析显示孕周增加(OR1.67,95%CI1.25-2.22,p<0.001),执行该程序的无监督居民(OR4.63，95%CI2.17-9.90)，p<0.001)，VAVD指征为胎儿宫内窘迫(OR2.72,95%CI1.04-7.10,p=0.041),10分钟以下的手术时间（OR4.75，95％CI1.53-14.68，p=0.007）与OASI相关。母亲年龄增加与OASI风险降低相关(OR0.9,95%CI0.84-0.98,p=0.012)。
结论：执行VAVD时，妊娠周增加，无人监督的居民执行程序，胎儿窘迫作为真空指征，10分钟下的真空程序与OASI相关。相比之下,产妇年龄的增加被证明是一个保护因素.
