Bodner-Adler B, Bodner K, Kaider A, Wagenbichler P, Leodolter S, Husslein P, Mayerhofer K
Department of Gynecology and Obstetrics, University of Vienna Medical School, Vienna, Austria.
J Reprod Med. 2001 Aug;46(8):752-6.
To determine the risk factors for third-degree perineal tears during vaginal delivery and to investigate the relation between different types of episiotomy and the occurrence of such tears.
This retrospective multicenter study consisted of an analysis of data from the delivery databases of the University Hospital of Vienna and Semmelweis Frauenklinic Wien between February and July 1999. The study was restricted to a sample that included all women with uncomplicated pregnancy as well as uncomplicated first and second stages of labor, gestational age > 37 weeks and a pregnancy with cephalic presentation. Women with multiple gestations, noncephalic presentation, cesarean deliveries, shoulder dystocia and gestational age < or = 37 weeks were excluded from the study.
Among the 1,118 births, 37 women (3.3%) experienced third-degree perineal tears. The use of episiotomy per se and the type of episiotomy (midline) as well as forceps delivery, primiparity, large infant head diameter, prolonged second stage of labor and use of oxytocin were identified as risk factors for third-degree perineal tears during vaginal delivery. When analyzing different types of episiotomy, there was approximately a sixfold-higher risk of third-degree perineal tears in women undergoing midline episiotomy as compared to mediolateral episiotomy. A stepwise logistic regression analysis revealed that episiotomy, prolonged second stage of labor and large infant head diameter remained independent risk factors for third-degree perineal tears.
We found several risk factors for third-degree perineal tears. The use of midline episiotomy was associated especially with an increased risk of severe anal sphincter tears. To prevent women from long-term sequelae due to third-degree perineal tears, avoidable risk factors should be minimized whenever possible.
确定阴道分娩时三度会阴撕裂的危险因素，并研究不同类型会阴切开术与此类撕裂发生之间的关系。
这项回顾性多中心研究包括对1999年2月至7月维也纳大学医院和维也纳塞梅尔维斯妇产医院分娩数据库中的数据进行分析。该研究仅限于一个样本，其中包括所有妊娠无并发症以及第一和第二产程无并发症、孕周>37周且为头位妊娠的妇女。多胎妊娠、非头位、剖宫产、肩难产和孕周<或=37周的妇女被排除在研究之外。
在1118例分娩中，37名妇女（3.3%）发生了三度会阴撕裂。会阴切开术本身的使用、会阴切开术的类型（中线）以及产钳助产、初产、胎儿头部直径大、第二产程延长和催产素的使用被确定为阴道分娩时三度会阴撕裂的危险因素。在分析不同类型的会阴切开术时，与侧切术相比，接受中线会阴切开术的妇女发生三度会阴撕裂的风险大约高六倍。逐步逻辑回归分析显示，会阴切开术、第二产程延长和胎儿头部直径大仍然是三度会阴撕裂的独立危险因素。
我们发现了几个三度会阴撕裂的危险因素。中线会阴切开术的使用尤其与严重肛门括约肌撕裂风险增加有关。为防止妇女因三度会阴撕裂出现长期后遗症，应尽可能减少可避免的危险因素。
