Gonzalez-Díaz Enrique, Fernández Fernández Camino, Gonzalo Orden Jose Manuel, Fernández Corona Alfonso
Pelvic Floor Unit, Department of Obstetrics and Gynaecology, Complejo Asistencial Universitario de León (CAULE), Spain.
Department of Obstetrics and Gynaecology, Complejo Asistencial Universitario de León (CAULE), Spain.
Eur J Obstet Gynecol Reprod Biol. 2019 Feb;233:127-133. doi: 10.1016/j.ejogrb.2018.12.019. Epub 2018 Dec 20.
Operative vaginal delivery (OVD) is the most important risk fact for obstetric anal sphincter injury (OASI). Knowledge of possible risk factors for their occurrence may therefore reduce the likelihood of faecal incontinence. The aim is to analyse the effect of mediolateral episitomy and perineum characteristics on the occurrence of OASI in OVD.
Case-control study, which included 958 OVD that were reviewed in Pelvic Floor and Puerperium Clinic. The episiotomy and perineum characteristics of those women who experienced OASIs (n = 150) were compared with those who had no evidence of anal sphincter injury (n = 788).
In multivariate logistic regression analysis the factors which were independently associated were nulliparity, persistent occipitoposterior position, birthweight >3500 g, an angle of episiotomy <30°, a distance episiotomy-fourchette <5 mm and a distance of perineal body <30 mm. The analysis of subgroups show that only the multiparous women does not benefit from any feature of the episiotomy, and an angle greater than 30° and a distance episiotomy-fourchette >5 mm are associated with a risk reduction of OASI in nulliparous, perineal bodies ≤30 mm and occipitoanterior position.
Two modifiable risk factors at the time of performing the episiotomy, the angle and distance episiotomy-fourchette, have been identified as the risk modification of OASI. It is necessary to achieve an adequate angle to reduce the probability of OASIs in OVD, and in nulliparous women with an anterior position and a distance of perineal body ≤30 mm could benefit from increasing the episiotomy-fourchette distance.
手术助产阴道分娩（OVD）是产科肛门括约肌损伤（OASI）最重要的风险因素。因此，了解其发生的可能风险因素可降低大便失禁的可能性。目的是分析会阴侧切术和会阴特征对手术助产阴道分娩中产科肛门括约肌损伤发生情况的影响。
病例对照研究，纳入了在盆底与产褥期诊所接受检查的958例手术助产阴道分娩病例。将发生产科肛门括约肌损伤的女性（n = 150）与会阴侧切术和会阴特征与无肛门括约肌损伤证据的女性（n = 788）进行比较。
在多因素逻辑回归分析中，独立相关的因素有初产、持续性枕后位、出生体重>3500 g、会阴侧切角度<30°、会阴侧切至阴唇系带距离<5 mm以及会阴体长度<30 mm。亚组分析显示，只有经产妇未从会阴侧切术的任何特征中获益，而对于初产妇、会阴体长度≤30 mm且为枕前位的产妇，侧切角度大于30°和会阴侧切至阴唇系带距离>5 mm与产科肛门括约肌损伤风险降低相关。
已确定在进行会阴侧切术时两个可改变的风险因素，即侧切角度和会阴侧切至阴唇系带距离，可作为产科肛门括约肌损伤的风险修正因素。有必要获得合适的角度以降低手术助产阴道分娩中产科肛门括约肌损伤的概率，对于初产妇、胎位为前位且会阴体长度≤30 mm的产妇，增加会阴侧切至阴唇系带的距离可能有益。
